[3appleshigh]

is another word for 'Thread' in this instance, it is also a word used in sewing ie. stitch up a pant leg, and in the medical profession he took 25 stitches. But on a forum it is talking about the thread - or the post. I cannot find an reference to the internet lingo for this word, but that is to what it refer's.

here is the definition I could find:

STITCH

NOUN:

A single complete movement of a threaded needle in sewing or surgical suturing.

A single loop of yarn around an implement such as a knitting needle.
The link, loop, or knot made in this way.
A mode of arranging the threads in sewing, knitting, or crocheting: a purl stitch.
A sudden sharp pain, especially in the side. See Synonyms at pain.
Informal An article of clothing: wore not a stitch.
Informal The least part; a bit: didn't do a stitch of work.
A ridge between two furrows.
VERB:
stitched , stitch·ing , stitch·es
VERB:
tr.


To fasten or join with or as if with stitches.
To mend or repair with stitches: stitched up the tear.
To decorate or ornament with or as if with stitches: "The sky was stitched with stars" (Mario Puzo).
To fasten together with staples or thread.
VERB:
intr.

To make stitches; sew.

IDIOM:
in stitches Informal
Laughing uncontrollably.