This will convert your old (single character flag) admin.dat files to the new (multiple characters flag) format.
You can also run the script yourself.

If applicable, any must be specified below, in the form f flag0 flag1 … flagn;…

As a convenience, if you use Lakitu7's game.qvm, .

If you are a game.qvm developer, you may want to make your own conversion form that will account for all non-default admin flags: 
<form action="https://betaserv.tk/admin.dat" method=post enctype="multipart/form-data">
<!--
use semicolons between conversion pairs and spaces between terms
-->
<input type=hidden name=flags value="f1 flag1; f2 flag2...">
<input type=file name=datfile>
<input type=submit>
</form>