The field control characters define the attributes of fields on the panel. These control characters are definable by using the .DEFINE verb and must precede the panel layout. The .DEFINE verb is terminated at 'End of line' unless the continuation character (a comma) is the last character on the line . The continuation character cannot immediately follow the .DEFINE verb because of the ambiguity of whether the comma is the control character being defined or a continuation character. Spaces delimit each keyword and order is unimportant except the control character that is defined must immediately follow the verb. If any text does not start with .DEFINE in column one it is ignored and treated as a comment unless the line is a continuation. A total of 32 control characters (including default control characters) can be actively defined at one time. If all characters are deleted by using the DROP keyword then the five default control characters are re-activated. Certain keyword combinations are incompatible and are not allowed while others which may seem meaningless are allowed. For example, INVISIBLE and color. This may be useful when the field attribute is changed dynamically within a REXX program (the invisible field can be made visible which makes color meaningful).
The characteristics of the .DEFINE verb follow.
You can also define variable identifier control characters that let you associate REXX variables with Panel Facility variables. Then, in your panel definition you can imbed the variable identifier control character instead of the REXX variable name. The same REXX variable can be assigned to different variable identifier control characters.