taglines where witty one-liners posted at the end of messages, after the signature, as a way to add a bit of humor or personality.

I think we also used them in fidonet echomail, but I don't remember for sure.

The problem is that the nomenclature and conventions differed, and this many years later people tend to conflate them.

BBS networks like ILink had tearlines, optional taglines, and mandatory origin lines. FidoNet had tearlines and origin lines because it shared roots and sometimes nodes with the BBS networks; so they were there for compatibility. Usenet mainly had signatures, with all of its equivalents to the other stuff in headers.

* http://ftsc.org/docs/fts-0004.001

In echomail they were known as "Origin" because the intended purpose of that line was to identify the originating node. It looked like this:

  * Origin: any random text (12:34/56.78)