One letter

[WhizBang]

what's with the category "One Letter"? I've answered one but don't get the one letter aspect.

[Paucle]

The series I ran from mid June to mid August that ended...

2 days 0 hours - 2009-08-15
OK, I'm tired of looking for them. What's the difference
between the first & second half of my last 240 answers?
Answer: one letter


e.g., CaN/CuN
FiDDLE FaDDLE
pALL mALL
INsT/INcT

[Staley]

You did a series with the same twist several months earlier, too.

[WhizBang]

thanks...sometimes it takes me a while