Jenkins SCM polling currently recognizes the 'externals' property when set and checked-in to the repository.  For common repositories where externals differ depending on the project, it is not possible to permanently have this property set on the svn server.

Current workaround involves setting the 'externals' property manually by use of the 'bat' command step, however this means the externals are not included in the polling list.

It would be useful if the subversion plugin supported the 'propset svn:externals' command, and added the specified directories/files to the polling list.