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(Ballet) I agree that the extensions are more important than the primary, and that the best solution is to have the general keywords in both the extensions and the primary.
(Hirayama) The repetetion of "major" keywords (such as TELESCOP) was suggested by the HEASARC FITS Working Group when we met them at NASA/GSFC on May 28th, 2003. See also section titled "Answers to the questions" under topic 006 of the latest topics of FT1 and FT2 for more details. Because the FT1 definition changed quite a bit since then, it could be useful if some of us can meet the HEASARC FITS Working Group members to discuss on this topic.
2. HDUCLASS keywords
(Digel) I am not sure whether we adhere to the strict definition of a HDUCLASS1 = EVENTS file. The only column that we have in common with the specification of The Recommended Columns and Keywords for a FITS Event List is TIME.
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