A user here is hoping to find a non-PDF machine readable source that lists all changes in Census Subdivisions from 1981 through 2001, together with the coding and the CSD Type after each change. I suspect that she will have to go through each of the Standard Geographical Classifications, but hope to be pleasantly surprised.
The same information in a somewhat more usable format, ie as xls files, is available from the Interim list of changes to municipal boundaries, under DLI. We have pulled the files as per:
On the DLI ftp site, the files are (or rather were) in
/dli/geography/1991/document/interim/ and in /dli/geography/1996/interim/