1999.06.20 23:47 "TIFF Version 42 -> 45", by Niles Ritter

1999.06.20 23:47 "TIFF Version 42 -> 45", by Niles Ritter

Regarding the "next generation" TIFF version number 42 issue, should it become necessary to promote the value:

   TIFF version = 45


The choice of version number is very important. The number (42) was documented as to be changed only if there was such a radical change in the TIFF structure as to contain no useful information for a current TIFF compliant reader.

This issue has been raised regarding what the next version number should be (interestingly, 43 was not proposed, even though it is well known that software versions that are odd (especially prime) tend to work better than even or composite versions. I do not know why, but it even seems to apply to Beethoven symphonies).

Should it be necessary to change this value, the only appropriate value in the original spirit of the design would be 45.

Here is my chain of reasoning:

  1. In the original TIFF 4.0 specification, the value 42 was chosen "for its deep philosophical significance". In the later 5.0 and 6.0 spec the wording regarding 42 was changed to it being an "arbitrary but carefully chosen number".
  2. The reference is the "Hitchiker Guide to the Galaxy", in which "42" is revealed as the answer to the universe, raising the issue of what the "ultimate question" was.
  3. In a later part of Douglas Adams' story it was revealed that the ultimate question was "What is 6 x 9?".
  4. Endless debate regarding how 42 could be the correct answer (e.g, the string "42" is ambiguous, and could be correct in base 13) are moot in terms of TIFF, which having specified a binary (base 2) representation could not escape having an incorrect value.

Conclusion: if we wish to make TIFF "right", then the correct answer to the ultimate question (which in base 10 is represented as 45), should be installed into the next-generation TIFF header.

Ergo, version=45 (hex: 0x2d)

Ref: The Deep Thought "42" page at


(TIFF is given honorable mention).