GEFI - HELP !

New to forum & was reviewing past posts last night and saw various references to GIFI, thought must investigate further. Opened post this morning and my Notaire has sent me a letter in English emphasising how important it is to return 'enclosed fiscal kit' for 'GEFI Company immediately'. It is in French; I have no idea what it is, I assume from reviewing past posts that it is to do with VAT reclaim (which developer. is meant to give to me on receipt of last payment). Notaire's letter could be read as me having to just sign document, but I see lots of boxes for ticking. Would appreciate any help anyone can give me.

Thanks