I don't understand relationships like this. Instead of just the name of the related database there is a field, a backslash, then the name of the database, another backslash followed by another field. Here is a picture of an example.

How are these relationships created? Why are they used? Can anyone point me to an in depth reference that covers them?

 

What you're describing (and showing in your screenshot) is not a relationship; it is the name of a table occurrence (TO for short), which is an instance of a table, used (among other things) to create a relationship by relating one (or more) of its fields to those of another TO.

A TO can have the same name as its base table, but doesn't have to; within certain constraints, you're free to choose a (unique) name. Usually, that name conveys something about the base table and about the context and/or purpose of that TO within its solution – as, presumably, does the name of the TO in your screenshot.

Note that in FileMaker, a relationship itself does not have a name. 

I suggest you open the FileMaker Help (or get another resource, e.g. the FileMaker Training Series) and study the introduction(s) to the how & why of creating table occurrences and relationships. Understanding TOs is fundamental to developing in FileMaker.

Edited August 13, 201510 yr by eos

Thank you! OMG having the right term has made my day so much better. I will check out the FileMaker Training Series.