I too have had contact the Cemetery Bereavement Manager at Catheys when looking for my grandmothers grave....they are really helpful.
I did have her death certificate details giving her address which appeared to be important for them to know before they gave me the plot number. I found out that my grandfather was buried in the same plot many years later but his death certificate gave the address where he was found dead due to an accident
Data protection prohibited her from giving me the address he had been living at in 1925

...

, she sounded really sorry because she knew I needed it. Good old Cardiff Library found the newspaper cutting for me and all the world to see, with the address... data protection is so strange

Ambers