How long does a knot have to be tied to be considered a "קשר של קימא". (Knot of permanence).
A deeper understanding into the 5 conditions needed to fold something on Shabbos and one should be careful to fold their TALIS on Motzi...
Important Guidelines for Dealing with Lice or Nits on Shabbos, and What to Do if One Finds a Badly Wounded Animal;