REPLY: 1:104/57.0 4ec959e5   
   MSGID: 1:3634/12.73 5d7d8b69   
   PID: GED+LNX 1.1.5-b20180707   
   CHRS: CP437 2   
   TZUTC: -0400   
   TID: hpt/lnx 1.9.0-cur 17-02-17   
      
    On 2019 Sep 14 17:02:00, you wrote to me:   
      
    JM> Just out of curiousity, what's the recommended way of dupe checking   
    JM> these days, MSGID, TID/PID, CRC, combination there of (including Msg   
    JM> Header)?   
      
   MSGID is the main way but older software doesn't generate MSGID so other   
   methods need to be used...   
      
   trying to root back through 20 years of memory, i recall one tosser takes the   
   header + 20 or 40 bytes of the message body and runs that through a CRC32...   
   that gets the header and generally most of the control lines... with this in   
   mind, i specifically wrote my message posting tools to put the MSGID at the   
   top of the control lines so it was pretty much guaranteed to be in that block   
   of bytes that tosser grabbed for its CRC32... i do no recall any of the posts   
   made by those tools being reported as dupes by any system in the network...   
      
   other tossers take a more involved approach and CRC the header, CRC the   
   control lines, and CRC the message body... maybe even MD5 instead of CRC...   
   the problem then comes from those systems that mistakenly reformat the   
   messages as they process them and write the reformatted messages to new   
   PKTs... now the message body is different and will fail CRC/MD5 calcs...   
      
   some systems specifically CRC the message body to avoid dupes that are   
   identical even with different headers and control lines... this is apparent on   
   systems that only get, for example, one posting of an echos rules each month   
   and only accept new postings of those rules IF the message body is different   
   than the last... i can understand this reasoning but it thwarts the idea of   
   monthly rules postings... it also has problems when the message is purged for   
   age but the CRC database retains the CRC of the purged message... so that   
   results in there being no area rules in the area even though they are posted   
   monthly... the only workaround is to add the posting date to the message body   
   which is kinda rediculous because the header already contains that   
   information... plus, in my case, there was a new MSGID in each posting as   
   well... but those monthly posts were still duped out because of the body being   
   the exact same...   
      
   what i would do would be to ask other tosser devs what they use in their   
   code...   
      
   listed in no particular order:   
      
     tobias burchhardt  - fastecho   
     rob swindell       - sbbsecho   
     nick andre         - d'bridge   
     vince coen         - mbse's tosser   
     kim heino          - bbbs' tosser   
     wilfred van velzen - fmail   
     james coyle        - mystic   
      
   i'm sure there are others but these seem to be the most common ones being used   
   today...   
      
   )\/(ark   
      
   Once men turned their thinking over to machines in the hope that this would   
   set them free. But that only permitted other men with machines to enslave them.   
   ... Clear out, or I'll set the cats on you   
   ---   
    * Origin:  (1:3634/12.73)   
   SEEN-BY: 1/120 123 14/6 15/2 18/0 123/0 25 120 150 755 135/300 153/757   
   SEEN-BY: 153/7715 227/114 229/354 426 1014 240/5832 249/206 317 261/38   
   SEEN-BY: 280/464 300/4 317/3 322/757 342/200 633/0 267 280 281 412   
   SEEN-BY: 633/509 640/1321 1384 712/620 848 770/1 3634/0 12 15 24 119   
   PATH: 3634/12 640/1384 712/848 633/280 229/426