BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//archive.cryptologicfoundation.org//NONSGML kigkonsult.se iCalcrea
 tor 2.30.10//
CALSCALE:GREGORIAN
METHOD:PUBLISH
UID:3a6388be-620b-49da-8d50-5a7c7ac7cefa
X-WR-CALDESC:12 August 1918: The 'Allegheny' field code was issued. Learn a
 bout American Army Field Codes in a document by William Friedman via the l
 ink at the bottom of the page.\n\nTrench codes were codes used for secrecy
  by field armies in World War I. A reasonably-designed code is generally m
 ore difficult to crack than a classical cipher\, but of course suffers fro
 m the difficulty of preparing\, distributing\, and protecting codebooks. T
 he Americans adopted a series of codes named after rivers\, beginning with
  'Potomac'. They learned to print the codebooks on paper that burned easil
 y and degraded quickly after a few weeks\, when the codes would presumably
  be obsolete\, while using a font that was easy to read under trench condi
 tions.
X-WR-RELCALID:a3c979bcd2c88818435c0839bf2476c6
X-WR-TIMEZONE:America/New_York
BEGIN:VTIMEZONE
TZID:America/New_York
BEGIN:STANDARD
TZNAME:EST
DTSTART:20301103T020000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
RDATE:20311102T020000
RDATE:20321107T020000
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:EDT
DTSTART:20310309T020000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
RDATE:20320314T020000
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
UID:89854c71-7c64-4ca9-9aa1-cbb0883ab48f
DTSTAMP:20260428T051004Z
DESCRIPTION:12 August 1918: The 'Allegheny' field code was issued. Learn ab
 out American Army Field Codes in a document by William Friedman via the li
 nk at the bottom of the page.\n\nTrench codes were codes used for secrecy 
 by field armies in World War I. A reasonably-designed code is generally mo
 re difficult to crack than a classical cipher\, but of course suffers from
  the difficulty of preparing\, distributing\, and protecting codebooks. Th
 e Americans adopted a series of codes named after rivers\, beginning with 
 'Potomac'. They learned to print the codebooks on paper that burned easily
  and degraded quickly after a few weeks\, when the codes would presumably 
 be obsolete\, while using a font that was easy to read under trench condit
 ions.
DTSTART;TZID=America/New_York:20310812T000000
DTEND;TZID=America/New_York:20310812T235900
LOCATION:
SUMMARY:1918: 'Allegheny' Field Code was issued.
END:VEVENT
END:VCALENDAR