Need a list of common abbreviations used by posters

For example: OSAS

I am not ashamed to admit I am ignorant of what that means. I am not unwilling to learn and have just Googled it: Results below,
OSAS\tObstructive Sleep Apnea Syndrome
OSAS\tOpen Systems Accounting Software
[b][color=CC0000]OSAS\tOnce Saved Always Saved[/color][/b]
OSAS\tOhio Scottish Arts School

I am hoping the one I highlighted in red is correct. :-)

Kind regards,
white stone