[fitsbits] start of Public Comment Period on the INHERIT convention

[William Pence]

I share many of the concerns that others have expressed here about 
promoting the INHERIT convention into the FITS Standard.

It seems to me that the motivation for using the INHERIT convention to 
save what typically amounts to less than a few 100K bytes of disk space 
per file is now greatly diminished from when it was first developed back 
in 1995, since the cost of disk storage has dropped so dramatically. 
Also, data providers are now much more comfortable with more efficient 
ways of packing multiple data arrays into a single binary table (which 
were only officially approved the year before in 1994), instead of 
writing each array as a separate image extension. Thus, I think it is 
questionable whether this convention continues to serve a useful purpose.

Implementing this convention in FITS reading and writing software also 
seems to me to be a rather complex and somewhat ambiguous task.  It is 
not exactly clear what action should be taken with regard to preserving 
the inherited keywords during complex data processing operations where 
the values of some of the inherited keywords may be modified, or when 
copying an HDU which uses the INHERIT convention into another FITS file. 
  Because of these complexities, I have never attempted to support the 
INHERIT convention in the CFITSIO library.

So far, all the comments about the INHERIT convention have been quite 
negative.  Does anyone want to offer any positive comments in support of 
incorporating this convention into the FITS standard?

-Bill