SIAP and encoding of POS input parameter

[Thomas Boch]

Dear DALers,

While playing with some SIAP services the other day, I found out that
some of them did not like the declination part of the POS input
parameter to be started by a '+' (properly escaped as %2B).
Example : 
http://mysiap.org/query?POS=83.6,22.0144&SIZE=0.2      is understood
whereas:
http://mysiap.org/query?POS=83.6,%2B22.0144&SIZE=0.2   is processed as
an error.

After checking in the SIAP document, I found nothing explicit about how
the value of the POS parameter should be encoded.

Has anyone any comment on that ?
Cheers,

Thomas