This command converts immediate operand(s) type of the current instruction/data to an enum member. Before using this command, you have to define an enumeration type.
If the selected enum is a bitfield, IDA will try to build a bitfield expression to represent the constant. Please note that for bitfields having multiple constants with the same value some expressions won't be possible.
If a range is selected using the anchor, IDA will perform 'en masse' conversion. It will convert immediate operands of all instructions in the selected range to symbolic constants. However, IDA will ask you first the lower and upper limits of immediate operand value. If the operand value is >= lower limit and <= upper limit then the operand will be converted to offset, otherwise it will be left unmodified.
When you use this command, IDA deletes the manually entered operand.
If the cursor is on the first operand (the cursor is before ',') then the first operand will be affected; otherwise all other operands will be affected.
See also: Edit|Operand types submenu. Enter #th operand manually commands. Set operand type