My company uses Mac and they have a lot of filenames with
#. I noticed that using an external NAS (not Apple, but Synology or Qnap), the 'search' failed when it meet file with
# in a file name. Is this a limit of the AFP open source protocol version or some other reason?
I cannot speak for open source implementations of AFP, but Apple's implementation seems to have no trouble with it, either for file transfers or for searches. I just tried it with an OS X 10.7 (Lion) client and both 10.7 and 10.7 Servers, and everything worked as expected.