Whilst trawling through u.t.l. looking for a post about signalbox codes for BAET I came across the following list of two-letter codes for the JLE:
TF Green Park TG Charing Cross TH Waterloo TJ London Bridge TK Canada Water TL Canary Wharf TM North Greenwich TN Canning Town TP Southwark TR Bermondsey TU West Ham TW Stratford TY Stratford Market Depot
Now, that looks thoroughly wrong (and out of order to boot!). Did all the stations on the JLE really get assigned consecutive two-letter codes, and if so, did they really get assigned in the above order?