a few technical words to clearly define within this context versus other related contexts.

Ein großer Teil der Regestenarbeit wird neuerdings dem Forscher durch besondere Regestenwerke abgenommen, namentlich auf dem Gebiet der mittelalterlichen Urkunden. Daß diese bevorzugt werden, hat zwei Gründe: erstens sind die Urkunden fur die Geschichte des Mittelalters gewissermafen als festes Gerippe von besonderer Wichtigkeit; zweitens sind sie so verstreut in ihren Fund- und Druckorten, daß die Zusammenstellung derselben, wie sie ftir jede Arbeit von neuem erforderlich wire, immer von neuem die langwierigsten und mtthsamsten Vorarbeiten nötig machen würde. Es ist daher von größtem Nutzen, daß diese Vorarbeiten ein fir allemal gemacht und dem einzelnen Forscher erspart werden.

Google translation:

A large part of the regesta work has recently been relieved of the researcher by special regesta works, especially in the field of medieval documents. There are two reasons why these are preferred: first, the documents are of particular importance for the history of the Middle Ages as a solid skeleton; Secondly, they are so scattered in the places where they were found and printed that the compilation of them, as would be necessary for each new work, would again and again necessitate the most lengthy and laborious preparatory work. It is therefore of the greatest benefit that this preparatory work should be done once and for all and that the individual researcher be spared.

While the contexts are mixed here between note taking and historical method, there is some useful advice here that while taking notes, one should do as much work upfront during the research phase of reading and writing, so that when it comes to the end of putting the final work together and editing, the writer can be spared the effort of reloading large amounts of data and context to create the final output.

Derartige geordnete Eintragungen historischer Materialien nennt man Regesten, Regesta, eine Ableitung von dem Verbum regerere, das schon bei Quintilian in der Bedeutung ,abschreiben, eintragen“ vorkommt. Spezielle Zusammenstellungen der Aufenthaltsorte historischer Persönlichkeiten aus den Quellen nennt man Itinerare. (p 556-557)

Google translation:

Such ordered entries of historical material are called regesta, regesta, a derivation of the verb regerere, which already occurs in Quintilian in the meaning "to copy, to enter". Special compilations of the whereabouts of historical figures from the sources are called itineraries.

Regesta in this context are complete copies of ordered entries of historical material. One might also translate this as historical copies or entries.

While Bernheim is talking about historical records and copies thereof in his discussion of regesta, he does bring up a useful point about manual note taking practice: one needn't completely copy the original context, just do enough work to create context for yourself so as not to be overburdened with excess material later. Some working in digital contexts may find it easy to simply copy and paste everything from an original document, but capturing just the useful synopsis may be enough, particularly when the original context can be readily revisited.