On 18 Sep, 14:25, "John Rowland"
wrote:
very big snip
Stevenage is SG, and is represented.

Apologies for my typo (G is above V on a QWERTY keyboard and I managed
to hit the wrong one!). Oddly SV was the code for London Transport's
Stevenage bus garage.

My point was that Hertford (SG13 and SG14) is shown as being in CM
(Chelmsford), which it isn't and Ware (SG12) is shown as being in HP
(Hemel Hempstead), which it certainly isn't. The bit of St Albans (AL)
just outside Bishop's Stortford still has me confused though.