Converting home made request files version 2 of the request format

The request specification is mostly backward compatible. The only required changes are in the request header. Specifically the header of the fits extension must have the following keywords

• EXTNAME = 'PS1_PS_REQUEST' - same as V1
• EXTVER = '2'
• ACTION = 'PROCESS' - New keyword. PROCESS is currently the only supported value
• EMAIL = 'user@domain' - New keyword to set identify the user submitting the request file.

In the request specification rows, the new columns are not required to be set. The parser defaults them appropriately. Users are strongly encouraged to use the SURVEY (3PI, MD01, etc) in their requests. If it is missing or NULL the system sets it to 3PI for coordinate based lookups (REQ_TYPE bycoord and by skycell)