Fieldwork operations for the FYE 2021 FRS were rapidly changed in response to COVID-19 and the introduction of public health measures.
Cafodd gweithrediadau gwaith maes ar gyfer yr FRS FYE 2021 eu newid yn gyflym mewn ymateb i COVID-19 a'r mesurau a gyflwynwyd o ran iechyd y cyhoedd.