Based on a Naaleh.com shiur by Rabbi Shimon Isaacson
·The Mishna Berura notes that inserting a safety pin once into a garment is permitted, but making two “stitches,” i.e. sticking the pin into the cloth twice, is prohibited. This is based on the Korban Netanel who rules that a pin has the same halachic status as thread. Rav Moshe differs and maintains that a safety pin is not much different than a button and is permitted, if it will be temporary and is clearly noticeable.
·Brooches are normally inserted once and are therefore permitted according to both opinions.
·Gluing or sticking two pieces of paper together is similar in effect to sewing. Therefore, it is prohibited on Shabbos in the category of sewing.
·Diapers with adhesive tape should be opened before Shabbat. Taping the diaper onto a baby is permitted, as it is meant to be temporary. You should be careful when removing a soiled diaper not to close the tabs around the diaper, since they will remain that way permanently in the garbage. Diapers with velcro tabs are permitted because velcro achieves its stickiness by hooking, not by gluing. Today, most diapers are manufactured with a combination of velcro and adhesive tabs. Therefore, l’chatchila, one should be careful to open them before Shabbat and not re-stick the tabs when disposing.
·Stickers and Post-It notes should not be used on Shabbat.
·Magnets do not pose a problem of tofer, but may be a violation of kotev, writing.
·Suction cups have a medium of permanence and may be a violation of boneh, fixing something to a structure.
·Tightening or loosening the waistline belt of a skirt or pants is permitted.