| Number | Name | Date | Kind | 
|---|---|---|---|
| 4857017 | Erk | Aug 1989 | |
| 4952172 | Barkus et al. | Aug 1990 | |
| 5198279 | Beinhaur et al. | Mar 1993 | |
| 5252080 | Pesson | Oct 1993 | |
| 5584728 | Cheng | Dec 1996 | 
| Entry | 
|---|
| 3.6 Accessories, 48 B (Secretariat) 296, two pages. | 
| Tempus CBC 20 Coding System, ITT Cannon brochure, p. 65, date unknown. | 
| 3.6 Accessories, SP-3179, one page, Sep. 9, 1994. | 
| Accessories Board-to-Board Coding System, Berg Electronics brochure, pp. 72 and 73, date unknown. |