[Proj] towgs84 values for EPSG:27700

[Hermann Peifer]

On 19/02/2012 21:06, support.mn at elisanet.fi wrote:
>
> So the reason for the difference is that the OSGB36
> datum is not any standard value.
>

I am aware that there always might be many values for a single EPSG 
code. I also don't want to debate in how far the values of the "ETRS89 
(WGS84) to OSGB36/ODN Helmert transformation", on p. 33 of [1], can be 
considered as "standard values". My simple (slightly rephrased) question 
was:

ogr2ogr -s_srs epsg:27700 # expands to something
cs2cs -v +init=epsg:27700 # expands to something else

Is this expected behaviour?

Hermann

[1]
http://www.ordnancesurvey.co.uk/oswebsite/gps/docs/A_Guide_to_Coordinate_Systems_in_Great_Britain.pdf