The power of exclude in ISPF edit

I hope most people know about the ISPF edit exclude facility.  You can issue commands like

X ALL /* exclude every thing */
F XXXX ALL
F YYYYY ALL WORD
DELETE ALL X  /* delete everything which is excluded */
RESET
X ALL 
F ZZZZ all 
F AAAA all
FLIP  /* make the excluded visible, and the displayed hidden */
CHANGE 'ABC' 'ZYX' ALL NX /* do not change hidden lines */

You can also exploit this in macros.  See ISREDIT XSTATUS.

/* rexx */ 
ADDRESS ISPEXEC 
'ISREDIT MACRO' 
"ISREDIT EXCLUDE 'AAA' ALL PREFIX" /* just like the command*/
"ISREDIT LOCATE .ZLAST" /* go to the last line */ 
"ISREDIT (r,c) = CURSOR" /* get the row and column number */
/* r has the row number of the last line */ 
do i = 1 to r 
    "ISREDIT (xnx) = XSTATUS "i 
    say "Line exclude status is" i xnx    
    "ISREDIT (line) = LINE " i  /* extract the line */
    if (...) then 
    "ISREDIT XSTATUS "i" = X"   /* exclude it */
end 

You can also see if a line has been changed this edit session:

"ISREDIT (status) = LINE_STATUS "i /* for line i */
if (substr(status,8,1) = '1') then 
say "Line" i " was changed this session "