Confusing DB schema files

[jlmuir]

In ISPyB/documentation/database, there are three different DB schema files:

File                        Last Modified
--------------------------  -------------
ISPyB_DataModel.mwb         6 months ago
ISPyB_DataModel_5.11.1.mwb  5 months ago
ISPyB_DataModel_5.mwb       8 months ago

The top-level README.md links to ISPyB_DataModel_5.mwb, yet, of the three, that's the oldest by last-modified time.

Which one is the authoritative version?

Can the others be removed?

If the others cannot be removed, a README.md in the directory would be useful to make it clear what the three .mwb files are for and which one should be updated for which purpose.