I've been seeing this stupid stencil around the 'hood for the last year or so and never quite knew what it was all about.  Directions to your friendly neighborhood acid supplier? Guerrilla street marketing for a Ford pick-up with a respectable turning radius?  Anything at all?

Well, We Built This City finally put the pieces together for all us curious folk:

Who else recognizes this? It’s the sign from Mission approaching S. Van Ness

And she's right!

Thank you, WBTC. I can finally sleep at night.