A Disturbing Development: Signs

Familiar symbols have been spotted by undisclosed sources in and around the Brampton area. This hitherto unmarked part of the world would appear to be in the early stages (Stage 3 at most) of corruption, but, needless to say, there is every reason to be alarmed. Reports are crude at best, but the symbols, as far as I can tell, resemble this:


The precise nature of the markings is unfamiliar, notably the thin "head" line. I have yet to analyse it with any real thoroughness, and am anxious for ideas.

Yours as ever,
Sir P----