reply to stjeromeslibido at https://www.reddit.com/r/Zettelkasten/comments/10qw4l5/comment/j6x52ce/?utm_source=reddit&utm_medium=web2x&context=3

Luhmann often used the shorthand of red numbers to indicate a link to nearby card in the current branch/stem, which Scott Scheper calls "stemlinks" in Antinet Zettelkasten (2022) p234. So, for example, on card ZKII 9/8 there is a red "1" which indicates the branching card ZKII 9/8,1. Scott uses a more computer science oriented notation of "/1" to indicate this as if he were traversing up or down a folder structure. Since there isn't really a (useful) idea of a root or home folder, and one wouldn't often want to refer to their zettelkasten itself, one might consider using the solidus "/" to indicate the current card? I personally do this, but not very frequently, though I might do it more often with respect to indicating argumentation within and among other cards.

Some languages have location/proximity identifiers or markers (similar to here/there/over there). I'll sometimes use the Japanese markers (ko-so-a-do) as shorthand to provide rough approximation of idea relationships particularly when I have open questions. (example: kore, sore, are, dore -> this one, that one, that one over there, which one?) Many ideas are marked あ to indicate "just out of reach" or "needs additional thought". When ideas are adjacent or nearby, but by happenstance are relatively far away within my ZK (with respect to physical card distance in the box) they'll be pre-pended like こ/510/4b/3 (aka "ko"/510/4b/3).