This creates headers in the current FITS header that record the supplied provenance information.

The tabulated indexed headers below, all with string values, are written for each ancestor NDF. The keyword index n is the provenance identifier for each NDF, starting at 0 corresponding to the current NDF. All have value ’ $<$unknown$>$’ if the information could not be found, except for MORE information; the PRVMn header is omitted if there is no MORE information to record.

Keyword Comment

• —— ——- PRVPn Path of the $<$nth$>$ parent PRVIn Identifiers of direct parents for $<$nth$>$ ancestor PRVDn Creation date of $<$nth$>$ parent PRVCn Creator software of $<$nth$>$ parent PRVMn Contents of MORE of $<$nth$>$ parent

where $<$nth$>$ is the appropriate ordinal string, e.g. 1st, 2nd, 3rd, 4th.

The above headers are prefaced by a blank header and a title " Provenance:" comment. There is a blank header between each set for improved legibility.

CALL CVG_WPROV( IPROV, FUNIT, STATUS )

IPROV = INTEGER (Given)

FUNIT = INTEGER (Given)

STATUS = INTEGER (Given and Returned)

• Supports up to 9999 ancestors.

• The PRVPn, PRVIn, and PRVMn keywords may often need more than the maximum 68 characters allowed in a keyword character value. Therefore this routine uses the non-standard Long-string Keyword Convention that permits long strings to continue over multiple headers. If any of the aforementioned keywords’ values exceeds 68 characters, this routine adds a warning in some COMMENT headers and writes a LONGSTRN header, whose value is the version of the convention being used.

The FITS file must already be open. The current HDU in the FITS file should be the primary and the standard headers should have been written.