DESI-COSMOS and DESI-XMMLSS Spectroscopic Redshift VAC Review (DR2)

Contact Person: Joshua Ratajczak
2 catalog files (fits), 1 README

Initial Checks:
- [X] Includes README
- [x] Columns in ALLCAPS
- [X] Extension names in ALLCAPS
- [x] Files include units
- [x] VAC publication passed CWR

Initial Notes:
- Thank you for including extension names.
- The FITS data tables have columns that are a mix of cases. We usually prefer ALLCAPS, but it appears that many of the columns are copied from other sources. If there is no harm in making the column names ALLCAPS, can you please do that?
- The data tables do not have any units (*i.e.* TUNIT keywords) that I can see. Can you please add units?
- There are a number of columns that appear to have `TNULLxxx` header keywords. Those could cause subtle issues and should only be used if really necessary.
- In both FITS files the first data HDU has invalid DATASUM and CHECKSUM keywords. The other HDUs do not have checksum information at all. Please add verified checksum information to all the HDUs.
- Finally, both files have a very unusual empty HDU 0, this example is from DESI-COSMOS.fits:
```
SIMPLE = T / conforms to FITS standard
BITPIX = 8 / array data type
NAXIS = 0 / number of array dimensions
EXTEND = T
M =
E =
R =
G =
E =
END
```
Can you please remove the `MERGE`?