The scheme is kept under review and any proposals to change it would need to be considered as part of this wider review process and subject to separate consultation.
Caiff y cynllun ei adolygu'n rheolaidd a byddai angen i unrhyw gynigion i'w newid gael eu hystyried fel rhan o'r broses adolygu ehangach hon a bod yn destun ymgynghoriad ar wahân.