Developers use to comment the table in the relationships graph adding text notes.
And many developers come up with a "naming convention" for Tutorial: What are Table Occurrences? that tell them in a kind of "shorthand" which table occurrence is part of a given group and thus how it links to other tables occurrences. This can save time and group related TO's together in the menus that appear in various location where you need to set up a reference to a field by first picking the table occurrence.
for example, might be a TO with Invoice as its base table, but in an anchor buoy set of table occurrences where customer is the name of the anchor. |dataentry might then be the text that identifies the intended purpose of this TO.
Please note that there are many different variations to this and it's more important that you pick one that works for you and that you are consistent in using it than it is for you to pick any one method over another.