Paul,
The sequences for the BAAVSS visual charts have all been entered into the database. When you try to upload a visual observation, it’s checked against the sequence.
[Deletia
If you use an AAVSO chart, our DB doesn’t have any sequence information for these charts.
Ah, there’s a thing.
In principle the AAVSO sequences could also be added to the BAAVSS database (assumng they are not there already – I don’t know). Those of us doing ensemble photometry generally include the (instrumental,catalogued) values for the (magnitude, error) of those sequence members which are measurable.
In principle, the BAA database could run sanity checks using those sequences too. Either that, or I am missing something.
Further, the AAVSO database could be scraped occasionally (once a year perhaps) to see what comparison stars have changed. What to do after a change should be obvious — pretty much what happens for BAA sequence changes.