Check http://downloads.teradata.com/download/database/dbql-scripts for migration scripts.
Changes should be indicated and in the "Data Dictionary" manual -> "Changes to This Book", maybe in the "Release Summary" manual, too (didn't check).
Not sure it's a correct place for this comment but there's something wrong with DBQL downlaods:
Migration scripts for v12 to v13 is missing !
Migration from 13 to 14 mentioned twice !:
Migration from v2r6 to 12 exist.
Whome i should contact for the missing v12 to v13 scripts.