The federal compilation of administrative regulations currently in force, and is published annually, so must be updated to reflect regulations that are newly promulgated, revised, or repealed.
The chronological compilation of new and amended regulations, both proposed and final.
A current unofficial electronic version of the C.F.R., eCFR is essentially an editorial compilation of CFR material and Federal Register amendments, so many researchers use the eCFR as an updating tool; the current update status is printed at the top of e-CFR pages. Using the eCFR makes it unnecessary to use the List of CFR Sections Affected (LSA) to update regulations. However, Boolean searching is not yet possible in this version – you must browse by C.F.R. title and part.
LSA is an updating tool to update the CFR, and can be used to track a regulation through the Federal Register.