In Administration > Configuration there are a number of configuration values.

key	default	meaning	availabe since OpenMeetings version
user.login.minimum.length	4	minimum chars required for the login to create a user	1.9.x
user.pass.minimum.length	4	minimum chars required for the password to create a user	1.9.x
number.minutes.reminder.send	15	minutes the one-time reminder in the calender is send, set to 0 to disable reminder	1.9.x
max_upload_size	1073741824	Maximum size of upload file (bytes) 1073741824 bytes = 1GB	1.8.x
show.whiteboard.draw.status	0	Display name of the user who draw the current object (User Name auto-disapper after 3 seconds.	1.8.x
use.old.style.ffmpeg.map.option	0	If the system should "." (old ffmpeg) instead of ":" (new ffmpeg) for the -map option in FFMPEG	1.9.x
inviter.email.as.replyto	1	Set inviter's email address as ReplyTo in email invitations (1 == set, 0 == NOT set)	2.0.x
office.path		The path to OpenOffice/LibreOffice (optional) please set this to the real path in case jodconverter is unable to find OpenOffice/LibreOffice installation automatically	2.0.x