OLL = off-list lower, a receiver that isn't on the list of named assault weapons.
Here is a list of acronyms that are commonly used on the forum, http://www.calguns.net/calgunforum/s...hlight=acronym
. Yes, there are a lot, and not all are documented, but you need to read and you will start to pick up the lingo. Most of us aren't gonna take the time to spell out "off list lower", "registered assault weapon" "law enforcement officer", etc and are just gonna say OLL, RAW, LEO, etc.