Any existing term which allows, for example a landlord to provide any statement verbally or issue any notice over the telephone would be incompatible with the fundamental term.
Byddai unrhyw deler presennol sy'n caniatáu, er enghraifft, i landlord roi unrhyw ddatganiad ar lafar neu roi unrhyw hysbysiad dros y ffôn yn anghydnaws â'r teler sylfaenol.