a land transaction relating to land in Wales has an effective date before 1 April 2018, but is not notifiable for SDLT purposes; and
oes gan drafodiad tir sy’n ymwneud â thir yng Nghymru ddyddiad dod i rym cyn 1 Ebrill 2018 ond nad yw’n hysbysadwy at ddibenion TDDS; ac