TR1 - Martial Status

Compiling the TR1 for the first time. I live in Ireland most of the time but spouse lives abroad all the time. He is foreign and has no pps number.

My question is what should I write in place of his pps no. as it is not possible to explain that on the TR1.

"Married but living apart" is probably the best option? As you say, the options on the form don't really cater for all situations and in my experience, writing explanatory notes on covering letters seems to be a waste of time as it only leads to more, largely irrelevant, queries.