this was posted in USCIS website when EB3 Retrogression in the end of 2004.
http://uscis.gov/graphics/lawsregs/handbook/VisaRegrssn122904.pdf
"Pipeline" cases refers to those Form I-485s Physically received on or before Cut off date, in hte appropriate service office but subsequently affectd by a regression.
Pipeline cases will be held in abeyance until such time as a visa number becomes available. Pipeline cases will be considered to be pending during this period, and applicants will be eligible to apply for interim benefits such as EAD and AP.