William Thompson wrote:
I was reviewing a document suggesting keywords to be used in FITS
headers, and I was wondering if there was any kind of defacto standard
beyond that in the FITS definition. The keywords being suggested were
as follows

INSTRUME FITS Standard
TELESCOP FITS Standard

DETECTOR The detector used
INSTITUT The institution
OBSERVAT The observatory
NETWORK I think this keyword is meant to be used for data
taken by a network of observatories, such as the GONG
network.

CFHT uses INSTRUME, DETECTOR, and OBSERVAT.