Editing Envelope (section)

=== International standard sizes <!--'ISO 269 redirects here'--> ===
[[International standard]] '''ISO 269''' (withdrawn in 2009 without replacement<ref>{{Cite web |title=A4 Letter or Legal |url=https://noidue.de/en/a4-letter-or-legal/ |access-date=2022-10-09 |website=Noidue |language=en-US}}</ref>) defined several standard envelope sizes, which are designed for use with [[ISO 216]] standard [[paper sizes]]:

{| class="wikitable sortable"
|+ International standard envelope sizes
|-
! Format !! Dimensions (mm) !! Dimensions (in) !! [[Aspect ratio|AR]] !! Suitable content format
|-
!title="designated long"| DL <!--(M65){{qn}}-->
| {{size|110|220|ar=on}} || {{frac|1|3}} A4
|-
! C7
| {{size|81|114|ar=1.414}} || A7 (or {{frac|1|2}} A6)
|-
! C7/C6
| {{size|81|162|ar=on}} || {{frac|1|3}} A5
|-
! C6
| {{size|114|162|ar=1.414}} || A6 (or {{frac|1|2}} A5 or {{frac|1|4}} A4)
|-
! C6/C5
| {{size|114|229|ar=2}} || {{frac|1|3}} A4
|-
! C5
| {{size|162|229|ar=on}} || A5 (or {{frac|1|2}} A4)
|-
! C4
| {{size|229|324|ar=1.414}} || A4
|-
! C3
| {{size|324|458|ar=1.414}} || A3
|-
! B6
| {{size|125|176|ar=1.414}} || C6
|-
! B5
| {{size|176|250|ar=1.414}} || C5
|-
! B4
| {{size|250|353|ar=1.414}} || C4
|-
! E4
| {{size|280|400|ar=on}} || B4
|}
The German standard [[Deutsches Institut für Normung|DIN]] 678 defines a similar list of envelope formats.

DL comes from the DIN Lang (German: "Long") size envelope which originated in the 1920s.