Explicación: I don't have time to research this, but the petroleum people are probably using ArcView for their mapping database, and this may refer to their legend: some Googling may clarify this for you
I'm guessing, but Good luck!
-------------------------------------------------- Note added at 4 hrs (2006-07-17 03:22:06 GMT) --------------------------------------------------
ps: the RKB may provide a further clue?
-------------------------------------------------- Note added at 4 hrs (2006-07-17 03:25:18 GMT) --------------------------------------------------
OK, I see it's the Kelly bushing elevation: no help there. Maybe Johannes was right the first time!
Guy Bray Estados Unidos Local time: 10:43 Especializado en este campo Idioma materno: inglés Pts. PRO en la categoría: 7