Nope, these are all intended.
In the future I expect there to be many taxa added from peculiar sources, and the best way to name a peculiar source, in general, is with a URL.
We'll see how well the URLs work out when the time comes. For now H. s. s. (which is not in the synthetic tree) is the only taxon we have coming from a peculiar source. (All other sources have abbreviations such as ncbi:.)
If someone has a better authority for that subspecies let me know - Linnaeus perhaps? I could use a BHL URL.