In 2.3 we moved all the DB columns to be signed and since then there is no way to change that attribute anymore (see MDL-27982).

But all the related methods / stuff were kept there for BC, so any plugin would continue working without modification.

This is about to:

1) Decide when we (TARGET_BRANCH) take rid of all those remaining methods completely.

2) Implement it, so the API / XMLDB Editor / manager (and all uses in tests) won't allow any sign attribute anymore.

3) Document it everywhere (upgrade.txt, docs, release notes) so people will know well in advance.

IMPORTANT NOTE: This will force TARGET_BRANCH to be only upgradeable from 2.3 and upwards (not from 2.2 anymore. Just to avoid forgetting it).

Ciao