Library /sys$common/syshlp/patchhelp.hlb CHECK, ECO, Parameters  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 eco-level
      Indicates one or more ECO levels that  have  been  applied.   ECO
      levels can be entered in:

           o  Comma-separated lists

           o  Colon-separated ranges

      Both comma-separated lists  and  colon-separated  ranges  can  be
      specified  on  the  initial  command line.  However, only one ECO
      level or one range of ECO levels can be entered in response to an
      ECO level prompt (ECO>).