I suppose that OpenERP translates the warning messages in _constraints and _sql_constraints automatically, like OpenERP translates the name fields, the help of the fields, ... There is not need to add _(...) to translate them.
There are a lot of _constraints and _sql_constraints without _(...) and only a few (the ones I have listed above) that includes them, so I suppose that the last ones are wrong.
I suppose that OpenERP translates the warning messages in _constraints and _sql_constraints automatically, like OpenERP translates the name fields, the help of the fields, ... There is not need to add _(...) to translate them.
There are a lot of _constraints and _sql_constraints without _(...) and only a few (the ones I have listed above) that includes them, so I suppose that the last ones are wrong.