Flag descriptor for implicit flagging

If a standard change-flag descriptor defines a process code with an index value of zero, the descriptor defines an implicit change flag.

Implicit flagging refers to the automatic application of a change flag to all the SSIs that are not changed (that is, to all unflagged instructions). For example, if the flag descriptor defines the process code as h0 as in the following example, then ASMXREF assumes that all unflagged instructions in that module are flagged with the implicit flag H0.

A unit should contain only one change-flag descriptor that defines an implicit change flag. If a unit contains more than one implicit definition, only the first one is accepted and the rest are ignored.

The following figure gives some examples of valid change-flag descriptors:
Figure 1. Sample change-flag descriptors
    FLAG REASON    RLSE   DATE     ORIGIN   COMMENTS
    ---- --------  ----   -------- -------  --------------------
    $H0= DA24     ,033   ,760718,  RM44   : CREATED
    $02= ZA34537   811,   770416   DDR    : CORRECT BALANCE
    $P2= PTR0336   983    871211          : FIX BLOCK ESCAPE
    $h1= SKI1223A  103    09/01/93 Sharon : Increase Date Field