The *.zdl file format originated with Zorbec's Decklist Builder, still perhaps one of the best deck builders out there. The file format is actually just an *.ini file that's been renamed. Documentation on such a file format can be found here. Most major programming languages have libraries already set up for interpreting *.ini files, so this is one of the more trivial formats to read.

An example deck is below:

;
; Deck list generated by Zorbec's DeckList Builder
;
[General]
EventName=
PlayerName=
DeckTitle=Durin's Secret Society of Dear Friends
EventDate=
Team=
Author=Kralik
Email=
WebSite=
DeckFormat=Movie
PlayerID=
; • Frodo, Master of the Precious
RingBearer=5U111
; • The One Ring, Such a Weight to Carry
OneRing=7R2
; Dunharrow Plateau
Site1=7U329
; King's Tent
Site2=7U335
; Beacon of Minas Tirith
Site3=7U338
; Osgiliath Fallen
Site4=7U342
; City Gates
Site5=7U344
; Minas Tirith First Circle
Site6=7U347
; Osgiliath Crossing
Site7=7U353
; Northern Ithilien
Site8=7U359
; Slag Mounds
Site9=7U363
FreePeopleCount=3
ShadowCount=3
[FreePeople]
; 1 x • Sméagol, Poor Creature
CardID0=6C45
Qty0=1
; 1 x • Gimli, Feared Axeman
CardID1=7R7
Qty1=1
; 1 x • Sam, Son Of Hamfast
CardID2=1C311
Qty2=1
[Shadow]
; 3 x • Gollum, Old Villain
CardID0=6C40
Qty0=3
[Notes]
LineCount = 0
[ScratchPad]
Count=0

Following standard INI format, general sections are marked by section headers such as [FreePeople], and specific variables followed by their value, such as Qty0=0. Unique among the various deck formats, *.zdl as a result of its INI nature saves the specific position of each card, so in the example above Smeagol takes the first Free Peoples position, while Gimli takes the second, and so on. For those unfamiliar, the ; indicates a commented line, so those lines are strictly for human readability and are not required by any means.