245i
245i is the part of AC21 that has made my life so miserable.
Basically, under this section, there was a sunset provision for illegals to file for employment based immigration, with a sunset date of April 30th 2001. This then caused labor processing to come to a complete standstill from April 2001 to sometime in the last summer/fall of 2002 (at least for VA/Philly), since the SESAs, which were used to handling about 10,000 labor cases during the course of a whole year reported getting upwards of 30,000-40,000 cases in April 2001 itself.
These people who were eligible to file for EB (even though they were illegal) in 2001 are now getting their 140s, etc approved, and are coming up for the 485 adjudications. I guess since they were mostly working in the 'lower end' jobs (no requirement for a Masters degree, or extraordinary ability, etc), they mostly lie in the EB3 category.
I think I read on Murthy's newsletter that as a result of an increased number of EB3 485 petitions, they now expect the EB3 visa availability to retrogress.
Hope this helps.
K