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APPENDIX A. SYNTAX OF KEYWORD RECORDS

must be exactly equal to 80.}

FITS value keyword record :=

keyword field value indicator [space...] [value] [space...] [comment]

{Constraint: The total number of characters in a FITS value keyword record must be

exactly equal to 80.}

{Comment: If the value field is not present, the value of the FITS keyword is not de-

fined.}

keyword field :=

[keyword char...] [space...]

{Constraint: The total number of characters in the keyword field must be exactly equal

to 8.}

keyword char :=

`A'­`Z' | `0'­`9' | ` ' | `-'

COMMENT keyword :=

`C' `O' `M' `M' `E' `N' `T' space

HISTORY keyword :=

`H' `I' `S' `T' `O' `R' `Y' space

BLANKFIELD keyword :=

space space space space space space space space

value indicator :=

`=' space

space :=

`'

comment :=

`/' [ascii text char...]

ascii text char :=

space­`~'

anychar but equal :=

space­`<' | `>'­`~'

FITS Standard