How to Identify a Runner in the Wild

Imagine this scenario.  You are out for a walk, minding your own business, when suddenly you hear a rustling along the side of the trail.  Preparing for the worst, you brace yourself.  Out from the brush leaps...a runner. 
How does one prepare themselves for this?  How do you identify a runner in the wild of the trails around your hometown?  More importantly, how do you recognize one when they are mingling with you in a public area and protect yourself from the spout of splits, trivia, and running information that could burst forth from them at a moment's notice?
Fear not.  Here, I will teach you how to identify a runner when one is in your presence, and how to prevent them from thinking you want to hear every time that they have ever run.
Typical Markers of a Runner:
Sports bra tan lines: (Typically found only on the female runner)  As the serious female runner often sheds layers as temperatures go up, you can spot one using the telltale sports bra tan line peeking out from their tank top.  Depending on how late in the season it is, or how often the runner in question sheds layers during exposure to sunlight, the depth of the lines may be different.  If you ever see one with a clear white outline on someone who is a deep tan everywhere else, you should maintain eye contact and back slowly away while making soothing noises.
Watch tan lines:  These come often to the more serious runners.  As they are used for timing splits for intervals, long runs, and tempos, you will not find one on your less dedicated athletes.  Always keep your eyes peeled for this warning sign.
Sock tan lines:  You can find these on just about any runner.  If sock tan lines start appearing on your close friends or loved ones, it might be best to stage an intervention or confront them before they become a full-fledged runner.
Uncomfortably Small Biceps:  Runners are not at all known for their muscular strength.  As they aim more for muscle endurance and speed, they care very little for bicep size.  Even in males, you will note that the biceps are much smaller than the average size in non-running males.
Ill-Fitting Pants:  Often you will find that the pants of a runner don't fit as well as those of a non-runner.  They tend to be too large in one area and snug in another, especially in middle-distance runners.
Killer abs:  If you are out swimming with friends and you notice that one of them has a perfect six pack without doing core workouts nearly often enough to justify them, I would suggest that you end your friendship as swiftly and gently as possible.  Anything is better than befriending a runner.

Escaping an Interaction With a Runner:
Keep your eyes down.  Whatever you do, don't attempt to run away.  This will only excite them and cause them to chase you down.  Avoid any conversations that could lead back to running.  (Topics include exercise, food, weather, vacation, shoes, apparel, health, etc.)  Call your local authorities if you spot one out in the wild, and get help if you ever find yourself encountering one.