It's really pretty easy.  First, include the following EXEC on LISTSERV's
191 disk:
------------------------------------------------------------------------
/* This File access validation exit logs user GET requests.           */
tellme = "YOU"
ADDRESS COMMAND
ARG , req origin filelist . "*" fn ft .
IF req ^= "GET1" THEN EXIT 0
entry = DATE("U") TIME() LEFT(filelist,8) LEFT(fn,8) LEFT(ft,8) origin
"EXECIO 1 DISKW" fn "GETLOG A1 0 (VAR ENTRY FINIS"
CALL DIAG 8,"MSGNOH" tellme "LISTSERV sent" fn ft "from" filelist,
  "library to" origin"."
EXIT 0
------------------------------------------------------------------------
Next, for each file you want to keep track of, add a sixth field
"GETLOG" to its XXX FILEID entry (or to the *DEFAULT* line):
 
FSLOOKUP EXEC 00000006 FSV E5/200 GETLOG
 
That's all it takes.
 
Thereafter, every time someone GETs the file, two things will happen:
 
1)  A MSG will go to YOU indicating this event.  (If you don't want
this, get rid of the two statements above containing variable
"tellme.")
 
2)  An entry will be made in file FSLOOKUP GETLOG on LISTSERV's 191
disk that looks as follows:
 
10/06/89 19:20:33 FSV      FSLOOKUP EXEC     SAW84@UXRLVM1
 
FSV is the filelist to which FSLOOKUP EXEC belongs.  SAW84@UXRLVM1
is the requestor.