All changes to tower
| Date | Change | Source |
|---|---|---|
| 19 Dec 2016 | 2,3,5,6: nominal added; 4: nominal amended | David Kelly via e-mail |
| 24 Jan 2012 | 1-6: frame id added; frame info added | John Baldwin via database |
| 22 Jun 2011 | 1,4: nominal added | Chris Pickford via 00009440 |
| 28 Mar 2008 | Mon PN info added | David Floyd (Assn webmaster) via e-mail |