Let's reframe things here in part because it's highly illustrative of both the phrases as well as the specific question you raise.

Imagine Andy Matuschak reading Sonke Ahrens' How to Make Smart Notes (CreateSpace, 2017) and making notes on what he feels is important. As he reads, he does what is prescribed, namely, he restates the idea in his own words based on what he's read. In doing this he takes the idea of "evergreen" content from journalism settings (and later SEO settings) which he was familiar with and applies that name to what Ahrens called permanent notes to expound on his understanding of Ahrens! (An evergreen article in newspaper work is an article which was written for a particular recurring holiday, event, or story and is regular. Why spend huge amounts of staff time writing that truly original Valentine's day article? The broad stories about gifts to give and restaurants to visit really don't change from year to year. Just dust it off and reprint it, as readers are unlikely to have saved or remembered it and it becomes free re-purposable content.)

Of course, in rewriting this definition, Matuschak adds in some additional baggage for those who aren't carefully reading his work. He adds some additional emphasis on revisiting one's ideas and rewriting them over time, which is certainly fine, but I think the novice note maker puts too much emphasis on this portion thinking that each permanent or evergreen note must eventually become polished to perfection. In practice, most seasoned writers don't and won't do this. In fact, I suspect if you looked at Matuschak's note on evergreen notes, you'd find that it probably hasn't changed since the day he wrote it other than agglutinating links from other notes.

This doesn't mean that one can't modify or change their ideas over time, this is certainly useful and good, but I suspect that the majority aren't doing it the way that might be imagined by Matuschak's original statement or the way that his idea was picked up by the (niche) digital gardening community and spread primarily in the work of Maggie Appleton. It's some of this evolution of Matuschak's definition which bled into digital gardens, which have some overlap with zettelkasten and the note taking realms, which have muddied the waters. As a result, one should take it as general advice and apply it to their own situation, needs, and practice.

For those who use their own notes for writing, one will often mark their cards/notes to indicate that they've used those ideas in various projects so that they're not actively repeating themselves ad nauseum. Some of the additional tweaks one might make to their notes from a style or context specific perspective are also left to the editing portion rather than being done in the notes themselves. As a result of some of this, unless there is a dramatic flaw in a note, there isn't generally a lot of additional work one would come back to it to revise it. If it does require that sort of major revision, then perhaps the better method would be to make a new note and linking it to the original along with an explanation of the error. I typically wouldn't recommend polishing individual notes to some Plationic idea of perfection. Doing so is often just make-work which distracts from one's time which could be better spent doing additional reading or actual thinking. If you're going to do that sort of polishing work, do it at the end when you've got a longer piece of writing you're including your note in.

The real question now, is how are you personally going to define permanent notes, evergreen notes, or other related phrases like atomic notes? This practice is called by Mortimer J. Adler and Charles Van Doren "coming to terms" with an author's work and is part of their analysis for how one should read a book to get the most out of it. I highly recommend reading How to Read a Book (Simon & Schuster, 1972 or Touchstone, 2011) as a companion to any of the usual note taking manuals.

If you want to continue the experiment on a better unified definition of permanent notes, evergreen notes, atomic notes, etc., you can find a pretty solid bibliography of note making, writing, and reading manuals to peruse at https://boffosocko.com/2024/01/18/note-taking-and-knowledge-management-resources-for-students/#Recommended%20reading.

While one could certainly go down the rabbit hole of reading all these resources, I would recommend only looking at one or two and spending your time working on actual practice. It's through practice that you're more likely to make actual progress on your own problems and questions.

reply to u/franrodalg at https://www.reddit.com/r/Zettelkasten/comments/1azoo9m/permanent_vs_evergreen_notes_am_i_thinking_about/

"unfiled notes" as "fleeting notes" which aren't expanded upon and turned into "permanent notes"

how are these related to his "fringe thoughts"

C. Wright Mills' idea of "fringe-thoughts" is similar to Ahrens framing of "fleeting notes".

https://www.flickr.com/photos/hawkexpress/189972899/in/album-72157594200490122/

Despite being used primarily as a productivity tool the PoIC system also included some features of personal knowledge management with "discovery cards" and "citation cards". Discovery cards were things which contained one's own ideas while the citation cards were the ideas of others and included bibliographic information. Citation cards were tagged on the 5th block as an indicator within the system.

Question: How was the information material managed? Was it separate from the date-based system? On first blush it would appear not, nor was there a subject index which would have made it more difficult for one to find data within the system.

https://www.reddit.com/r/antinet/comments/18hhnyo/carlink_collective_vs_branch_collective/

"Card link collective" and "branch collective"? Why is the jargon for keeping a card index becoming so arcane? Isn't it tough enough for something so simple?

https://forum.zettelkasten.de/discussion/1894/the-official-luhmann-certified-100-note-categories

So much to unpack here...

What is the full list of types of links?

There are (associative) links created by the author (of an HTML document) as well as associative (and sometimes unwritten) mental links which may be suggested by either the context of a piece and the author's memory.

There are the links made by the reader as they think or actively analyze the piece they're reading. They may make these explicit in their own note taking or even more strongly explicit with tools like Hypothes.is which make these links visible to others.

tacit/explicit<br /> suggested mentally / directly written or made<br /> made by writer / made by reader<br /> others?

lay these out in a grid by type, creator, modality (paper, online, written/spoken and read/heard, other)

reply to u/IamOkei at https://www.reddit.com/r/Zettelkasten/comments/17beucn/comment/k5s6aek/?utm_source=reddit&utm_medium=web2x&context=3

u/IamOkei, I know you've got a significant enough practice that not much of what I might suggest may be helpful beyond your own extension of what you've got and how it is or isn't working for you. Perhaps chatting with a zettelkasten therapist may be helpful? Does anyone have "Zettelkasten Whisperer" on a business card yet?! More seriously, I occasionally dump some of my problems and issues into a notebook, unpublished on my blog, or even into a section of my own zettelkasten, which I never index or reconsult, as a helpful practice. Others like Henry David Thoreau have done something like this and there's a common related practice of writing "Morning Pages" that you can explore. My own version is somewhat similar to the idea of rubber duck debugging but focuses on my own work. You might try doing something like this in one of Bob Doto's cohorts or by way of private consulting sessions. Another free version of this could be found by participating in Will's regular weekly posts/threads "Share with us what is happening in your ZK this week" at https://forum.zettelkasten.de/. It's always a welcoming and constructive space. There are also some public and private (I won't out them) Discords where some of the practiced hands chat and commiserate with each other. Even the Obsidian PKM/Zettelkasten Discord channels aren't very Obsidian/digital-focused that you couldn't participate as an analog practitioner. I've even found that participating in book clubs related to some of my interests can be quite helpful in talking out ideas before writing them down. There are certainly options for working out and extending your own practice.

Beyond this, and without knowing more of your specific issues, I can only offer some broad thoughts which expand on some of the earlier discussion above.

I recommend stripping away Scheper's religious fervor, some of which he seems to have thrown over lately along with the idea of a permanent note or "main card" (something I think is a grave mistake), and trying something closer to Luhmann's idea of ZKII.

An alternate method, especially if you like a nice notebook or a particular fountain pen, might be to take all of your basic literature/fleeting notes along with the bibliographic data in a notebook and then just use your analog index cards/slips to make your permanent notes and your index.

Ultimately it's all a lot of the same process, though it may come down to what you want to call it and your broad philosophy. If you're anti-antinet, definitely quit using the verbiage for the framing there and lean toward the words used by Ahrens, Dan Allosso, Gerald Weinberg, Mark Bernstein, Umberto Eco, Beatrice Webb, Jacques Barzun & Henry Graff, or any of the dozens of others or even make up your own. Goodness knows we need a lot more names and categories for types of notes—just like we all need another one page blog post about how the Zettelkasten method works by someone who's been at it for a week. Maybe someone will bring all these authors to terms one day?

Generally once you know what sorts of ideas you're most interested in, you take fewer big notes on administrivia and focus more of your note taking towards your own personal goals and desires. (Taking notes to learn a subject are certainly game, but often they serve little purpose after-the-fact.) You can also focus less on note taking within your entertainment reading (usually a waste) and focusing more heavily on richer material (books and journal articles) that is "above you" in Adler's framing. You might make hundreds of highlights and annotations in a particular book, but only get two or three serious ideas and notes out of it ultimately. Focus on this and leave the rest. If you're aware of the Pareto principle or the 80/20 rule, then spend the majority of your time on the grander permanent notes (10-20%), and a lot less time worrying about the all the rest (the 80-90%).

In the example above relating to Marx, you can breeze through some low level introductory material for context, but nothing is going to beat reading Marx himself a few times. The notes you make on his text will have tremendously more value than the ones you took on the low level context. A corollary to this is that you're highly unlikely to earn a Ph.D. or discover massive insight by reading and taking note posts on Twitter, Medium, or Substack (except possibly unless your work is on the cultural anthropology of those platforms).

A lot of the zettelkasten spaces focus heavily on the note taking part of the process and not enough on the quality of what you're reading and how you're reading it. This portion is possibly more valuable than the note taking piece, but the two should be hand-in-glove and work toward something.

I suspect that most people who have 1000 notes know which five or ten are the most important to where they're going and how they're growing. Focus on those and your "conversations with texts" relating to those. The rest is either low level context for where you're headed or either pure noise/digital exhaust.

If you think of ideas as incunables, which notes will be worth of putting on your tombstone? In other words: What are your "tombstone notes"? (See what I did there? I came up with another name for a type of note, a sin for which I'm certainly going to spend a lot of time in zettelkasten purgatory.)

https://lacountylibrary.libnet.info/event/9097350

https://www.youtube.com/watch?v=xMF37TXAV5w

Presenter Lawrence Mak broke down types of notes into the following three categories:<br /> - general notes (projects, ideas, journals, recipes, budgeting, homework, etc.)<br /> - lists (groceries, reading, gifts, to dos, assignments) - reminders (birthdays, bills, maintenance, health)

There's an interesting dichotomy which seems to be arising here. It's almost as if he's defining a folgezettel note in opposition to orphaned notes, most often seen in digital settings when importing lots of "stuff" but which Doto indicates can happen in analog systems as well.

Orphaned notes in an analog space, however are still linked by proximity even though they're not as densely linked (even from a mathematical topology perspective.)

"So long as it happens." And here lies the rub: when will you put in the work to make the note useful and actionable? Will it be now or later?

Some notes are certainly more mission critical than others. Some work towards one's life's work while others are tidbits which may be useful at a later time. Distinguishing along this spectrum isn't always easy, particular in build a bottom up view of one's research.

https://www.youtube.com/watch?v=vww7JLcrJl4

8:05 - 16:20 GTD - Capture - Clarify - What is it? - Is it actionable? What is the action? - Is it a project? - Batching - Reflect - Review over lists/calendars daily/weekly - Engage

17:30 They use the phrase "atomic" paper based index cards, so they've been infected by the idea of "atomic notes" from somewhere, though it seems as if he's pitching that he's "invented" his card system as if from scratch.

19:45 He mentions potentially using both sides of the card, against the usual (long term) advice.

20:00 Analogizes his cards as ballerinas which work together, but each have their own personalities and function within the ballet

He's using a leather cover for Moleskine pocket notebook and Manufactum A7 index cards, as well as a box

Sections of his box: - to erase - inbox - next actions - projects (3 categories of projects) - someday - to delegate - tickler (by month and by day; 12 months and 31 days) - blank cards

Mentions erasing cards as he finishes them rather than archiving them.

Inspiration by How to Take Smart Notes by Ahrens

Recommends one item per card to make things easier and more actionable; also improves focus versus having a longer list. (28:00)

Portability

Sustainable (he erases)

High quality textile experience

The ability to shift between associative modes and sequential modes seems to work well with such a system.

They distinguish between atomic notes and "stellar" notes. Stellar being longer lists or more dense notes/outlines/etc.

Project cards<br /> titles and project numbers (for reference) Project numbers in the top right with a P and/or M below it for<br /> - P for paper<br /> - M for email data<br /> - D for digital files which helps him find reference materials

Weekly review with all cards out on the table

Expansion pack includes: - action - calendar - waiting

Search was quick and easy, but had to carry his box back and forth to work.

Stopping doing it because he was losing the history (by erasing it). Moving to notebook and he likes fountain pens. He likes the calendar portion in his notebook.

He tried it out for the sake of experiment.

In the paper world things are more present and "in your face" versus digital formats where things can disappear.

reply to Edmund at https://forum.zettelkasten.de/discussion/comment/18550/#Comment_18550

@Edmund since I don't do such a thing myself, I'm curious what sort of affordance your #type/NoteName tagging provides you with (especially if you're using more than just those two)? Do you use them regularly for search or filtering, and if so for what reason? How does it help?

To me it look likes extra metadata/work, but without a lot of direct long term value in exchange. Does doing this for long periods of time provide you with outsized emergent value of some sort that's not easy to see from the start?

Not only a short description of the broad standard form of cards in Phyllis Diller's gag file, but also an enumeration of some of the non-standard cards, many of which are specified because of the issues which they presented in scanning/digitizing for transcription.

https://www.dtsheffler.com/blog/2014-07-21-two-goals-of-note-taking/ archive version: https://web.archive.org/web/20220528093415/https://www.dtsheffler.com/blog/2014-07-21-two-goals-of-note-taking/

ᔥ[[abramdemski]] in The Zettelkasten Method (accessed:: 2023-08-25 12:00:07)

This is the first time I've seen someone use the phrase "ghost note" to mean a future implied note which could be created by using wiki syntax [[*]] which in some systems like Obsidian or WikiMedia creates a (red) link which one could click on to create that note.

via u/THX-Eleven38 at https://www.reddit.com/r/Zettelkasten/comments/14ox2tw/what_is_the_proper_way_to_create_a_moc_note_from/

Within the pantheon of types of notes there are: - paraphrasing notes, which one can use to summarize ideas for later recall and review as well as to check one's own knowledge and understanding of what an author has said. - commentary notes, which take the text and create a commentary on them, often as part of having a conversation with the text. These can be seen historically in the Midrashim tradition of commenting on Torah.

[23:12 - 24:47]

separately also: - productivity notes - to do lists, reminders of work to be done, often within or as part of a larger complex project

Notes can be used for different purposes.

• productivity
• Knowledge
  • basic sense-making
  • knowledge construction and dispersion

The broad distinction is between productivity goals and knowledge. (Is there a broad range I'm missing here within the traditions?) You can take notes about projects that need to be taken care of, lists of things to do, reminders of what needs to be done. These all fall within productivity and doing and checking them off a list will help one get to a different place or location and this can be an excellent thing, particularly when the project was consciously decided upon and is a worthy goal.

Notes for knowledge sake can be far more elusive for people. The value here generally comes with far more planning and foresight towards a particular goal. Are you writing a newsletter, article, book, or making a video or performance of some sort (play, movie, music, etc.)? Collecting small pieces of these things on a pathway is then important as you build your ideas and a structure toward some finished product.

Often times, before getting to this construction phase, one needs to take notes to be able to scaffold their understanding of a particular topic. Once basically understood some of these notes may be useless and not need to be reviewed, or if they are reviewed, it is for the purpose of ensconcing ideas into long term memory. Once this is finished, then the notes may be broadly useless. (This is why it's simple to "hide them with one's references/literature notes.) Other notes are more seminal towards scaffolding ideas towards larger projects for summarization and dissemination to other audiences. If you're researching a topic, a fair number of your notes will be used to help you understand the basics while others will help you to compare/contrast and analyze. Notes you make built on these will help you shape new structures and new, original thoughts. (note taking for paradigm shifts). These then can be used (re-used) when you write your article, book, or other creative project.

Raul Pacheco-Vega uses five different types of index cards (notes): - direct quotations - bibliographic references - one idea index card (a major idea or them in one or two sentences) - summaries - combined (or content) index card

Pacheco-Vega defines a "combined" or "content index card" or one might say a content note as a one with "direct quotations, draft notes and ideas, conceptual diagrams, etc. that are associated with" the work in question. These seem similar to Ahrens' fleeting notes, though seem a bit more fleshed out.

a subtle catch about Ahrens' terminology

https://www.reddit.com/r/Zettelkasten/comments/zl2hwh/is_the_concept_of_personal_knowledge_management/

This essay seems to be more about shiny object syndrome. The writer doesn't seem to realize any problems they've created. Way too much digging into tools and processes. Note the switching and trying out dozens of applications. (Dear god, why??!!) Also looks like a lot of collecting digitally for no clear goal. As a result of this sort of process it appears that many of the usual affordances were completely blocked, unrealized, and thus useless.

No clear goal in mind for anything other than a nebulous being "better".

One goal was to "retain what I read", but nothing was actively used toward this stated goal. Notes can help a little, but one would need mnemonic methods and possibly spaced repetition neither of which was mentioned.

A list of specific building blocks within the methods and expected outcomes would have helped this person (and likely others), but to my knowledge this doesn't exist as a thing yet though bits and pieces are obviously floating around.<br /> TK: building blocks of note taking

Evidence here for what we'll call the "perfect system fallacy", an illness which often goes hand in hand with "shiny object syndrome".

Too many systems bound together will create so much immediate complexity that there isn't any chance for future complexity or emergence as the proximal system is doomed to failure. One should instead strive for immediate and excessive simplicity which might then build with time, use, and practice into something more rich and complex. This idea seems to be either completely missed or lost in the online literature and especially the blogosphere and social media.

people had come up with solutions Sadly, despite thousands of variations on some patterns, people don't seem to be able to settle on either "one solution" or their "own solution" and in trying to do everything all at once they become lost, set adrift, and lose focus on any particular thing they've got as their own goal.

In this particular instance, "retaining what they read" was totally ignored. Worse, they didn't seem to ever review over their notes of what they read.

I was pondering about different note types, fleeting, permanent, different organisational systems, hierarchical, non-hierarchical, you know the deal.

Why worry about all the types of notes?! This is the problem with these multi-various definitions and types. They end up confusing people without giving them clear cut use cases and methods by which to use them. They get lost in definitional overload and aren't connecting the names with actual use cases and affordances.

I often felt lost about what to takes notes on and what not to take notes on.

Why? Most sources seem to have reasonable guidance on this. Make notes on things that interest you, things which surprise you.

They seem to have gotten lost in all the other moving pieces. Perhaps advice on this should come first, again in the middle, and a third time at the end of these processes.

I'm curious how deeply they read sources and which sources they read to come to these conclusions? Did they read a lot of one page blog posts with summarizations or did they read book length works by Ahrens, Forte, Allosso, Scheper, et al? Or did they read all of these and watch lots of crazy videos as well. Doing it "all" will likely lead into the shiny object syndrome as well.

This seems to outline a list of specifically what not to do and how not to approach these systems and "popular" blog posts that are an inch deep and a mile wide rather than some which have more depth.

Worst of all, I spent so much time taking notes and figuring out a personal knowledge management system that I neglected the things I actually wanted to learn about. And even though I kind of always knew this, I kept falling into the same trap.

Definitely a symptom of shiny object syndrome!

Yet another new name for a sub-type of notes, here he uses reformulation notes as a shorthand for the old advice to rewrite ideas you find in your own words. This advice is often suggested to accomplish two things: - avoid plagiarism - restatement of ideas in your own words is related to the Feynman Technique and assists one in learning and ensuring they understand the concepts

Dialectical notes are made at the level of syntopical reading and entail creating a conversation not only between the reader and the author, but create a conversation of questions and answers between and among many texts and the reader.

Conceptual notes are made during the analytical reading of a book and "give answers to questions about the truth and significance of the book."

Adler and Van Doren define structural note making as the sorts of questions one might ask at the level of inspectional reading including: - what kind of book is it? - what is it about? - what is the overall structure with respect to the argument the author intends to make?

If you give a title to your notes, "claim notes" are simply notes with a verb.<br><br>They invite you to say: "Prove it!"<br><br>- "The positive impact of PKM" (not a claim)<br>- "PKM has a positive impact in improving writer's block" (claim)<br><br>A small change with positive mindset consequences

— Bianca Pereira | PKM Coach and Researcher (@bianca_oli_per) October 6, 2022

Bianca Pereira coins the ideas of "concept notes" versus "claim notes". Claim notes are framings similar to the theorem or claim portion of the mathematical framing of definition/theorem(claim)/proof. This set up provides the driving impetus of most of mathematics. One defines objects about which one then advances claims for which proofs are provided to make them theorems.

Framing one's notes as claims invites one to provide supporting proof for them to determine how strong they may or may not be. Otherwise, ideas may just state concepts which are far less interesting or active. What is one to do with them? They require more active work to advance or improve upon in more passive framings.

link to: - Maggie Delano's reading framing: https://hypothes.is/a/4xBvpE2TEe2ZmWfoCX_HyQ

https://www.loom.com/share/a05f636661cb41628b9cb7061bd749ae

Synopsis: Maggie Delano looks at some of the affordances supplied by Tana (compared to Roam Research) in terms of providing better block-based user interface for note type creation, search, and filtering.

These sorts of tools and programmable note implementations remind me of Beatrice Webb's idea of scientific note taking or using her note cards like a database to sort and search for data to analyze it and create new results and insight.

It would seem that many of these note taking tools like Roam and Tana are using blocks and sub blocks as a means of defining atomic notes or database-like data in a way in which sub-blocks are linked to or "filed underneath" their parent blocks. In reality it would seem that they're still using a broadly defined index card type system as used in the late 1800s/early 1900s to implement a set up that otherwise would be a traditional database in the Microsoft Excel or MySQL sort of fashion, the major difference being that the user interface is cognitively easier to understand for most people.

These allow people to take a form of structured textual notes to which might be attached other smaller data or meta data chunks that can be easily searched, sorted, and filtered to allow for quicker or easier use.

Ostensibly from a mathematical (or set theoretic and even topological) point of view there should be a variety of one-to-one and onto relationships (some might even extend these to "links") between these sorts of notes and database representations such that one should be able to implement their note taking system in Excel or MySQL and do all of these sorts of things.

Cascading Idea Sheets or Cascading Idea Relationships

One might analogize these sorts of note taking interfaces to Cascading Style Sheets (CSS). While there is the perennial question about whether or not CSS is a programming language, if we presume that it is (and it is), then we can apply the same sorts of class, id, and inheritance structures to our notes and their meta data. Thus one could have an incredibly atomic word, phrase, or even number(s) which inherits a set of semantic relationships to those ideas which it sits below. These links and relationships then more clearly define and contextualize them with respect to other similar ideas that may be situated outside of or adjacent to them. Once one has done this then there is a variety of Boolean operations which might be applied to various similar sets and classes of ideas.

If one wanted to go an additional level of abstraction further, then one could apply the ideas of category theory to one's notes to generate new ideas and structures. This may allow using abstractions in one field of academic research to others much further afield.

The user interface then becomes the key differentiator when bringing these ideas to the masses. Developers and designers should be endeavoring to allow the power of complex searches, sorts, and filtering while minimizing the sorts of advanced search queries that an average person would be expected to execute for themselves while also allowing some reasonable flexibility in the sorts of ways that users might (most easily for them) add data and meta data to their ideas.

Jupyter programmable notebooks are of this sort, but do they have the same sort of hierarchical "card" type (or atomic note type) implementation?

For the second time Goutor mentions using different size cards for different note types, but doesn't specifically advise for it or provide a reason. Perhaps his advice for consistency and card size applies only to cards of particular types? (p28)

link to: https://hypothes.is/a/XPphjkNZEe2s3i9VV4qt1g

Incidentally he also specifically mentions 7x9" cards here too. How frequently used were these as a standard?

Jacques Goutor defines content notes as those that "are drawn in one way or another from the actual contents of the sources." He considers them the most important part of note taking as "they will eventually constitute the pieces of the mosaic." (p20)

He further breaks this type down into generally self-explanatory "quote notes" and "summary notes". (p20) He does advise that one writes out careful summaries so that one needn't do additional future work of writing notes on one's own notes. While he doesn't state it directly, the presumption in his presentation is that a well written summary can be directly used in one's future written project.

Compare this type of note to others like evergreen or permanent notes.

Goutor acknowledges that there are a variety of note types, but focuses on bibliographic notes, content notes, and self-help notes as being the most common and most important. (p12)

These first two are broadly self-explanatory, but the third should be intriguing given the other literature in which this type is rarely, if ever, used. We'll see what comes of it...

bibnote is another I've seen

Do we really need another new sets of names?! ;)

One day all of these different types will eventually be canonical...

https://notes.andymatuschak.org/z6f6xgGG4NKjkA5NA1kDd46whJh2Gt5rAmfX

Julius Reizen in reviewing over Umberto Eco's index card system in How to Write a Thesis, defines his own "insurance card" as one which contains "hard-to-classify thoughts, questions, and areas for further inquiry". These he would keep together so that they don't otherwise get lost in the variety of other locations one might keep them

These might be akin to Ahrens' "fleeting notes" but are ones which may not easily or even immediately be converted in to "permanent notes" for one's zettelkasten. However, given their mission critical importance, they may be some of the most important cards in one's repository.

link this to - idea of centralizing one's note taking practice to a single location

Is this idea in Eco's book and Reizen is the one that gives it a name since some of the other categories have names? (examples: bibliographic index cards, reading index cards (aka literature notes), cards for themes, author index cards, quote index cards, idea index cards, connection cards). Were these "officially" named and categorized by Eco?

May be worthwhile to create a grid of these naming systems and uses amongst some of the broader note taking methods. Where are they similar, where do they differ?

Multi-search tools that have full access to multiple trusted data stores (ostensibly personal ones across notebooks, hard drives, social media services, etc.) could potentially solve the problem of needing to remember where you noted something.

Currently, in the social media space especially, this is not a realized service.