For the most part, IBM and family thankfully included strong documentation on the back of their keyboards in the form of a rear label that usually displays the keyboard's part number along with a date of manufacture. A birth certificate, if you will. Thanks to these, we're able to date most IBM and family keyboards since 1981. However, the style, format and even data points for these rear labels has changed over time, thus this topic will serve as a gallery of known rear labels that can show how they've changed through time and from one OEM to another. Presently, there are 88 keyboard rear labels found/on record.
A rear label on an IBM and family keyboard is a form of per-keyboard documentation that in its most basic form usually displays a part number with a date of manufacture or assembly. It is with these that people can quickly identify and date a keyboard. These rear labels are also known as rear stickers or even birth certificates. Rear labels on IBM keyboards only became consistent in the early 1980s with Model F keyboards; previous types of keyboards such as Model Bs could have widely varied labelling if at all and usually dating such a keyboard relied on a cable tag instead.
During the era IBM and Lexmark manufactured keyboards, there could be two types of rear labels; the outer case (or simply outer or external) label and the internal assembly (inner) label. The outer case rear label is used to display information about the keyboard as a whole. The internal assembly rear label is used to display information regarding just this inner assembly along with the keycaps fitted to it as standard. See for below various examples of rear labels along with their main datapoints highlighted.
Unicomp and TGCS have abandoned using fully-featured internal assembly rear labels and instead rely on outer case rear labels for identification. Lenovo's use of internal assembly rear labels depends on the type of keyboard - their full-travel desktop keyboards generally lack them, but their ThinkPad laptop keyboard assembly derived products may use them.
Date: 1982-05-27
Keyboard type: Model F 5324 Floortop Keyboard
Source: https://www.flickr.com/photos/[email protected]/albums/72157649745488066
Outer case part number: P/N 1501100
Date: 1983-03 (approximate from "4546" shop date)
Keyboard type: Model F/XT PC Keyboard
Notes: https://deskthority.net/wiki/File:Cs-9000-rear-plate.JPG
Date: 1983-11 (week 47 of year)
Keyboard type: Model F 3104/3178 Terminal Keyboard
Source: https://webwit.nl/input/
Date: 1984-07
Keyboard type: Model F/XT PC Keyboard
Source: Archived from volatile eBay Kleinanzeigen listing
Date: 1984-10 (week 43 of year)
Keyboard type: Model F 3290/5080 104-key Terminal Keyboard
Source: Joe/Ellipse @ modelfkeyboards.com
Date: 1984-12 (approximate from "4989" shop date)
Keyboard type: Model F/XT PC Keyboard
Notes: The third value is believed to be the shop date as converting it to a real date gives a reasonable date for this keyboard to be made during
Source: Archived from volatile eBay listing
Date: 1985-01 (week 2 of year)
Keyboard type: Model F 3104/3178 Terminal Keyboard
Source: Admiral Shark's Keyboards
Date: 1985-02 (approximate from "5031" shop date)
Keyboard type: Model F 3101 Terminal Keyboard
Notes: The third value is believed to be the shop date as converting it to a real date gives a value very close to the date code on the keyboard's other rear label
Source: Archived from volatile eBay listing
Outer case part number: P/N 6450200
Date: 1985-02 (approximate from "5032" shop date)
Keyboard type: Model F/AT PC Keyboard
Source: Joe/Ellipse @ modelfkeyboards.com
Date: 1985-08-27
Keyboard type: Model F 122-key Terminal Keyboard
Source: TheMK#1822 (CC BY-NC-SA 4.0)
Date: 1985-11-07
Keyboard type: Model M Type I 122-key Terminal Keyboard
Source: TheMK#1822 (CC BY-NC-SA 4.0)
Date: 1986-02-26
Keyboard type: Model F 5291 Terminal Keyboard
Date: 1986-03 (week 13 of year)
Keyboard type: Model F 4704 Model 300 Expanded Alphameric Keyboard
Source: Joe/Ellipse @ modelfkeyboards.com
Date: 1987-11-10
Keyboard type: Model M Enhanced Terminal Keyboard
Source: Admiral Shark's Keyboards
Outer case part number: P/N 1391472
Date: 1987-12 (approximate from "5737" shop date)
Keyboard type: Model M Space Saving Keyboard
Source: Admiral Shark's Keyboards
Outer case part number: P/N 1392595
Date: 1988-02 (approximate from "5780" shop date)
Keyboard type: Model M Enhanced Terminal Keyboard
Source: Admiral Shark's Keyboards
Date: 1988-03-21
Keyboard type: Model M Screen Reader/2 Keypad
Source: https://deskthority.net/wiki/File:IBM_Screen_Reader_Pad_back.jpg
Date: 1988-05-02
Keyboard type: Model M Enhanced PC Keyboard
Source: Joe/Ellipse @ modelfkeyboards.com
Outer case part number: P/N 6019273
Date: 1989-02 (approximate from "6033" shop date)
Keyboard type: Model F 4704 Model 100 Functional Keypad
Source: Joe/Ellipse @ modelfkeyboards.com
Date: 1990-09-13
Keyboard type: Model M Space Saving Keyboard
Source: Joe/Ellipse @ modelfkeyboards.com
Date: 1991-06
Keyboard type: Model M3 Numeric Keypad
Source: Dario @ Dario'sCope (donated photo)
Date: 1991-07
Keyboard type: Model M3-based Laptop Keyboard Assembly
Source: Uberman765#1669 (donated photo)
Date: 1992-03-25
Keyboard type: Model M Enhanced PC Keyboard
Source: Joe/Ellipse @ modelfkeyboards.com
Date: 1992-12-13
Keyboard type: Model M2 Selectric Touch Keyboard
Source: TheMK#1822 (CC BY-NC-SA 4.0)
Date: 1993-06-15
Keyboard type: Model M Space Saving Keyboard
Source: Joe/Ellipse @ modelfkeyboards.com
Outer case part number: P/N 66G8362
Date: 1994-02-21
Keyboard type: Model M 5576-C01 TrackPoint II Keyboard
Source: Admiral Shark's Keyboards
Date: 1984-02-03
Keyboard type: Model F/XT PC Keyboard
Source: Admiral Shark's Keyboards
Outer case part number: P/N 2684674
Date: 1985-02-14
Keyboard type: Model F 6580 Displaywriter Type B Keyboard
Source: https://deskthority.net/viewtopic.php?t=13658
Date: 1986-01-12
Keyboard type: Model F 122-key Terminal Keyboard
Source: Admiral Shark's Keyboards
Date: 1986-06-09
Keyboard type: Model M Type I 122-key Terminal Keyboard
Source: Admiral Shark's Keyboards
Date: 1989-09-15
Keyboard type: Model M Type III 122-key Terminal Keyboard
Notes: Notable for having the inner keyboard assembly part number printed underneath the main part number (albeit in a smaller font)
Source: Admiral Shark's Keyboards
Date: 1990-03-12
Keyboard type: Model M Enhanced PC Keyboard
Source: Admiral Shark's Keyboards
Date: 1993-02-23
Keyboard type: Model M2 Selectric Touch Keyboard
Source: Admiral Shark's Keyboards
Date: 1993-06-25
Keyboard type: Model M2 Selectric Touch Keyboard
Notes: Admiral Shark's Keyboards
Date: 1997-06-17
Keyboard type: Model M Type IV 122-key Terminal Emulator Keyboard
Source: Admiral Shark's Keyboards
Outer case part number: P/N 1397003
Date: 1997-06-17
Keyboard type: Model M Type IV 122-key Terminal Emulator Keyboard
Source: Admiral Shark's Keyboards
Date: 1987-07-14
Keyboard type: Model M Type II 122-key Terminal Keyboard
Notes: Has no visible date, thus date must be read from the internal rear label.
Source: https://deskthority.net/viewtopic.php?p=500098#p500098
Outer case part number: P/N 0985955
Date: 1987-07-14
Keyboard type: Model M Type II 122-key Terminal Keyboard
Source: https://deskthority.net/viewtopic.php?p=500098#p500098
Date: 1995-01-17
Keyboard type: Model M Enhanced PC Keyboard
Source: Archived from volatile eBay listing
Date: 1992-01 (week 2 of year)
Keyboard type: Model M4 Space Saver Numeric Keypad
Source: Archived from volatile eBay listing
Date: 1992-12-15
Keyboard type: Model M6 Laptop Keyboard Assembly
Source: Admiral Shark's Keyboards
Date: 1993-02-10
Keyboard type: Model M6 Laptop Keyboard Assembly
Notes: Lexmark used this minimalist rear label for AR-10 and GS-20 type laptop keyboards
Source: TheMK#1822 (CC BY-NC-SA 4.0)
Date: 1993-07-22
Keyboard type: Model M5-2 Trackball Keyboard
Source: Archived from volatile eBay listing
Date: 1993-12-14
Keyboard type: Model M5-2 Trackball Keyboard
Source: Admiral Shark's Keyboards
Date: 1994-07-15
Keyboard type: Model M6-1 Laptop Keyboard Assembly
Notes: Admiral Shark's Keyboards
Date: 1994-07-18
Keyboard type: Model F 5291 Terminal Keyboard
Source: https://webwit.nl/input/
Date: 1994-08-11
Keyboard type: Model M6-1 Laptop Keyboard Assembly
Notes: Admiral Shark's Keyboards
Outer case part number: P/N 92G7461
Date: 1995-01-09
Keyboard type: Model M13 TrackPoint II Keyboard
Source: Admiral Shark's Keyboards
Date: 1995-01-23
Keyboard type: Model M13 TrackPoint II Keyboard
Source: Admiral Shark's Keyboards
Date: 1995-02-06
Keyboard type: Model M6-1 Laptop Keyboard Assembly
Source: Admiral Shark's Keyboards
Outer case part number: P/N 92G7455
Date: 1995-05-05
Keyboard type: Model M5-2 Trackball Keyboard
Notes: Admiral Shark's Keyboards
Date: 1995-05-26
Keyboard type: Model M7 50-Key RPOS MSR Keyboard
Source: Archived from volatile eBay listing
Date: 1995-06-19
Keyboard type: Model M7-1 50-Key RPOS Keyboard
Source: TheMK#1822 (CC BY-NC-SA 4.0)
Date: 1995-07-24
Keyboard type: Model M Industrial Space Saving Keyboard
Source: Joe/Ellipse @ modelfkeyboards.com
Date: 1995-08-03
Keyboard type: Model M4-1 Space Saver Numeric Keypad
Source: Admiral Shark's Keyboards
Date: 1995-10-17
Keyboard type: Model M Enhanced Keyboard with Speaker
Source: Admiral Shark's Keyboards
Date: 1995-11-06
Keyboard type: Model M Enhanced Terminal Keyboard
Source: Admiral Shark's Keyboards
Date: 1995-11-13
Keyboard type: Model M15 Numeric Keypad
Source: https://webwit.nl/input/
Date: 1996-03-15
Keyboard type: Model M4 Space Saver Keyboard
Source: Admiral Shark's Keyboards
Date: 1998-10-05
Keyboard type: Model M13 TrackPoint II/FSR Industrial Keyboard
Source: Admiral Shark's Keyboards
Date: 1999-04-14
Keyboard type: Model M4-1 Space Saver TrackPoint II Keyboard
Source: Admiral Shark's Keyboards
Date: 2004-04-26
Keyboard type: Model M13 FSR Keyboard
Source: Admiral Shark's Keyboards
Date: 2005-03-28
Keyboard type: Model M Type IV 122-key Terminal Emulator Keyboard
Source: Admiral Shark's Keyboards
Date: 2007-08-28
Keyboard type: Model M Space Saving Keyboard
Source: https://webwit.nl/input/
Date: 2017-04-05
Keyboard type: Model M Type IV 122-key Terminal Emulator Keyboard
Source: Admiral Shark's Keyboards
Date: 2019-01-24
Keyboard type: Model M SpaceSaver Keyboard
Source: Admiral Shark's Keyboards
Date: 2019-05-22
Keyboard type: Model M EnduraPro Keyboard
Source: Admiral Shark's Keyboards
Date: 2020-11-10
Keyboard type: New Model M Space Saving Full-Sized Keyboard
Source: Admiral Shark's Keyboards
Date: 2021-01-26
Keyboard type: Model M Space Saving Keyboard
Source: Admiral Shark's Keyboards
Date: 1996-07-04
Keyboard type: Model M9 RANPOS Keyboard
Source: Admiral Shark's Keyboards
Date: 1997-07-23
Keyboard type: Model M13 TrackPoint II Keyboard
Notes: Maxi Switch removed the "M9" designation for this USB version of the original RS485 M9, but for all intents and purposes, it's still an M9
Source: Admiral Shark's Keyboards
Date: 2000-02-18
Keyboard type: Model M9 RANPOS Keyboard
Source: Admiral Shark's Keyboards
Date: 2000-11-03
Keyboard type: Model M9 RANPOS Keyboard
Source: Archived from volatile eBay listing
Date: 1996-06-03
Keyboard type: Model M6-1 Laptop Keyboard Assembly
Notes: One of two examples of a "KTC2" M6-1 rear label, made in Mexico. The format and styling seems identical to Lexmark M6-1 rear labels.
Source: Volvo B5234T#0733 (donated photo)
Date: 1996-09-02
Keyboard type: Model M6-1 Laptop Keyboard Assembly
Notes: One of two examples of a "KTC2" M6-1 rear label, made in Mexico.
Source: Admiral Shark's Keyboards
Date: 1998-01-30
Keyboard type: Model M6-1 Laptop Keyboard Assembly
Notes: One of two examples of a "KTC3" M6-1 rear label, made in Mexico.
Source: Admiral Shark's Keyboards
Date: 1998-05-11
Keyboard type: Model M6-1 Laptop Keyboard Assembly
Notes: One of two examples of a "KTC3" M6-1 rear label, made in Mexico.
Source: Admiral Shark's Keyboards
Date: 2004-07-13
Keyboard type: Model M7 50-Key RPOS MSR Keyboard
Source: Admiral Shark's Keyboards
Date: 2006-07-14
Keyboard type: Model M11 RPOS Modifiable Layout Keyboard
Source: Admiral Shark's Keyboards
Date: 2006-11-29
Keyboard type: Model M8 50-Key RPOS LCD Keyboard
Source: Admiral Shark's Keyboards
Date: 2008-03-26
Keyboard type: Model M7-1 50-Key RPOS Keyboard
Source: Archived from volatile Mercado Livre listing
Date: 2006-05-18
Keyboard type: "Model M-e" PS/2 ANPOS Keyboard
Source: Admiral Shark's Keyboards
Date: 2008-07-10
Keyboard type: "Model M-e" CANPOS Keyboard
Notes: Admiral Shark's Keyboards
Date: 2011-09-22
Keyboard type: "Model M-e" 67-Key MPOS Keyboard
Source: Admiral Shark's Keyboards
Date: 2012-06-06
Keyboard type: "Model M-e" MCANPOS Keyboard
Source: Admiral Shark's Keyboards
Date: 2012-06-21
Keyboard type: "Model M-e" 4613 96-Key POS Keyboard
Source: Admiral Shark's Keyboards
Date: 2013-06-20
Keyboard type: "Model M-e" 67-Key MPOS LCD Keyboard
Source: Admiral Shark's Keyboards
Date: 2014-02-24
Keyboard type: Model M7 50-Key RPOS MSR Keyboard
Source: Admiral Shark's Keyboards