Application for issue of ATPL - Classification of Hours

[Butter side-up]

Hi,

I am currently filling in the form to apply to unfreeze my ATPL.

The CAA licensing department are shut and so I was wondering whether anyone on this forum could answer my query.

On the form SRG\1137, there are references made to "Instrument Ground Time", "FNPT I" and "FNPT II / Flight Simulator".

What is "Instrument Ground Time" and how does it differ from the other two categories?

Thanks in advance for any help or advice on posting this query on another forum.

All the best.

BSU.