I noticed you have quite a few of these source tags (a bit over 132.000) like:
Edited over 13 years ago by pavel · Changeset #204763
Location: 49.6791040, 18.0824490
source HELP SERVICE - REMOTE SENSING spol. s r.o. http://www.bnhelp.cz
Is the service at this URL still something we want to link to? Is bnhelp a genuine resource?
Attaching source tags to individual elements was probably standard back then, recent edits would place it at changeset.