I just added the EF definition into the forum info box so it's easy to find. You're right that it was never defined here, so good catch! We want new visitors to find their way around easily.
In general, abbreviations become necessary when field space is limited, like in titles, but should be clearly defined somewhere handy.
In regular postings, we should all strive to clearly define an abbreviation or acryonm with it's first usage within a thread, (maybe even put it in bold type for easier finding), so somebody entering the site at that point would have the information right at hand. We can't assume a new visitor has read every thread in a forum, so having it defined in a previous thread wouldn't help.
Alas, I fear the acronym problem will get worse with the prevalence of texting. I often ask my teenager what certain acronyms mean. I'll write out full sentences on my texts, slowly hunting and pecking on my tiny phone keypad, and using proper grammar, only to get a cryptic reply of a few letters. It seems language skills are deteriorating at the same rate technology is advancing!
