determining which apps have entries in the applications menu in xfce

[Dan Hitt <dan.hitt@gmail.com>]

I'm using a pretty vanilla debian 9 with xfce.

There's an Applications menu in the upper left which has lots and lots
of applications listed under multiple submenus.

There's a program that i have on my system whose name i cannot find in
the Applications menu.

However, that might just be because i conducted a defective search.

So i'm wondering if there's a systematic way to determine if the
program is in the menu.  (Presumably it is a matter of looking in
/usr/bin or something like that, although that cannot be the complete
solution as there are a few thousand programs in /usr/bin, and they
cannot all fit in the menu.  So i suspect there's a list somewhere . .
. )

TIA for any clues on this,

dan