Methinks this thread has degenerated into uk.railway over analysis and
trying to put literal meaning behind words.

EB NB WB SB are merely vague terms in relation to compass directions
but very specific terms of opposing directions of running.

No more emphasis on EB NB SB WB should be taken than on Up and Down -
trains do not literally go Up or go Down.

OTOH, despite the fact that not all posters to this thread are in entire
agreement, I think we've learnt four things (all of which were new to
me, at least). I did know that LUL tracks were generally designated by
compass points rather than as up/down as used on the main railway
network, but I think I've learnt from this thread that:

1. The public signage doesn't always correspond to the designation of
the tracks.

2. The circle line tracks are designated as inner and outer (although
the public signage is based on compass points -- see 1 above).

3. Some lines change designation along their length; others don't, even
if that means their direction may not particularly correspond to their
designation (but see 1 above)

4. (I think) Where lines change designation along their length, they
remain with WIND (West/Inner/North/Down) and OUSE (Outer/Up/South/East)
-- so a Westbound track can change designation to a Northbound track but
not to a Southbound track.

Have I understood right?

-roy