This post was inspired by a feedback provided by one of the commenters on this post. The requirement was to exclude certain third party symbols from being published to the symbol server. I thought I would take upon the challenge to implement this.
As suggested in the same comment thread, my approach would revolve around explicitly setting the FileList property in the PublishSymbols activity. I would set it to a list that includes only the symbols that I want published. And the symbols I want to be excluded would be handled through a wild card filter that is passed as a build template parameter.