Make OBC an official abbreviated name of the project

OBC abbrevation had been circulating here and there but never officially mentioned. I think it is ok that it would collide with some [other OBCs](https://en.wikipedia.org/wiki/OBC) such as "OBC (secret society), at the University of North Carolina at Asheville" ;)
May be then even versions of the forms (see #42 ) should include it (`OBC-`) as a prefix.

Review the project's current public naming and the forms discussed in #42. Decide whether the abbreviation should be documented and whether form versions should use the OBC- prefix; done means the chosen naming is recorded consistently.

Written by the indexing model from the issue text.