what it is update-desktop-database (KDE)?

[macintoshzoom]

On OpenBSD 4.4-current (GENERIC.MP):

# cd /usr/ports/x11/kde/kdeutils
# make update
===> Updating for kdeutils-3.5.9p0
Upgrading from kdeutils-3.5.9p0
New package kdeutils-3.5.9p0 contains potentially unsafe operations
         @exec /usr/local/bin/update-desktop-database
Can't safely update to kdeutils-3.5.9p0 (use -F update to force it)
/usr/sbin/pkg_add: kdeutils-3.5.9p0:Fatal error
*** Error code 1

Stop in /usr/ports/x11/kde/utils3 (line 1472 of 
/usr/ports/infrastructure/mk/bsd.port.mk).
#

does this means kdeutils-3.5.9p0 is already updated?
If so I don't need to execute /usr/local/bin/update-desktop-database, 
unless It can reset, clean or improve something, if I discover what.

Does anyone knows what exactly it does this 
/usr/local/bin/update-desktop-database ?

Will damage, or replace some of my customizations or settings?

Can't find info about this:

$ man update-desktop-database
man: no entry for update-desktop-database in the manual.
$

$ /usr/local/bin/update-desktop-database --help
Usage:
   update-desktop-database [OPTION...] [DIRECTORY...]

Help Options:
   -?, --help            Show help options

Application Options:
   -v, --verbose         Display more information about processing and 
updating progress
   -q, --quiet           Don't display any information about about 
processing and updating progress
$

Thanks!

Mac.