Yes, if you also want to edit a text, frequency, TG or service type you can do that but be careful as each data are separated by an invisible tabulator character, so don't mess that up. It's easier if you import the database in an Excel type of program as a tab delimited format and then edit. It will then save back to the same format.
But when edit you should probably not use that file but instead the much smaller ones that are one file for each State. In the beginning of the database file you can see what number each state has, it is also in the hpdb.cfg text file, and that then has a s_0000xx.hpd file that you can edit.
I don't know which file, the hp1 or the hpd, that are actually used in Sentinel for the database. I think it is the hpd file and that hp1 file that have all info for all states are probably for doing compare to database when you do Discovery. Or it is actually the DB file for HP1/2 scanners. But the file has all systems, even the ones the HP1/2 scanner do not support. But maybe it is filtered in the scanner somehow.
/Ubbe