This year I am pleased to be involved with helping a small museum get established with an online presence. It is run by a team of dedicated volunteers who have a fairly large number of items which need to be catalogued. We decided at the outset that any system we designed should be compliant with the industry standards and so I have based the solution on Spectrum 5.0, which is the UK collection management standard produced by The Collections Trust.
I was recently asked to create a membership listing site where a key requirement was that there would be different users who could update the records of the members and the system admin would need to be able to keep track of the changes made by the other users. WordPress by default does not keep revisions of post meta data so I set about devising a solution. Searching online I came across an excellent post by John Blackbourn with many helpful pointers. So here is my solution for revisions of custom fields of a custom post type.