William Pence writes:
... There are only 3
proposed new absolute requirements in this list:

1. Keywords that have a value shall not be repeated in a header.

2. PCOUNT and GCOUNT must immediately follow the last NAXISn
keyword in all conforming extensions (as is already required
in IMAGE, TABLE, and BINTABLE extensions).

3. Embedded space characters are now forbidden within numeric
values in an ASCII Table (e.g. "1 23 4.5" is no longer
allowed to represent the decimal value 1234.5)

The public comment period on these, as well as all the other
recommended changes, remains open here on this email list/newsgroup
until at least the end of September...

Another proposed change, the case of the EXTEND keyword being made
optional, will also impose a software-change burden. Software which
previously relied on that keyword will now be required to check for
the presence of extensions in a different way.

Craig