https://en.wikipedia.org/wiki/User:Scarlsen
Turns out the answer was on Wikipedia already :).
It's weird to see times one has lived through presented as ancient history....
https://web.archive.org/web/20210108174645/https://www.adobe...
Bytes 2-3
An arbitrary but carefully chosen number (42) that further identifies the file as a TIFF fileNot mentioned in either the article or the tail end wikipedia article iamge was the early adoption of TIFF by the mapping and geodetic community to store raster line data (maps, images, and raw sat and instrument platform multichannel line data).
The tagging format made the embedding of spheroids, datums, projections, origins, lens and focal specifications relatively easy (plus or minus the usual Tower of Babel Tag Naming and Meaning Confusion).
righthand•2h ago
What a journey and congratulations to SC (don't want to spoil it) on your 15 minutes and rightful restoration as inventor of TIFF, take your place in history.