The difference between one letter or two letters; writing with a "SHINUI" (not the usual manner).
One letter on top of another letter.
Understanding the Concept of Leaving an Item on a Tree from Before Shabbos into Shabbos. Some Halachas About Using the Side of a Tree;
(Temporary Ohel) Important shailos which come up in conjunction with "Temporary Ohel" (Temporary roofing, temporary shelter);
What Should One Do If They Have Surveillance or Security Cameras, Burglar Alarms, etc. at Their Own House?;