Build id vs Version number in Synaptic

[Ralf Mardorf]

PPS:

If upstream provides sane versioning it's part of the package
versioning. However, since it's possible to build software with
different features [1] and/or against different versions of libraries
[2], the versioning of packages requires additional information.
Something more or less unique for Ubuntu is, that it additionally could
contain the relationship between Debian and Ubuntu packages.

[1] An example from a mailer. You could drop those features when
building, by not configuring with one or both options:
./configure --enable-bogofilter-plugin --enable-spamassassin-plugin

[2]
https://en.wikipedia.org/wiki/Soname