Disclaimer: I did some research for this question; I did not know all of this off the top of my head :P. Sources were found through the footnotes in Rabbi Ribiat's The 39 Melachos. It is forbidden to ...
What's the halachic problems if any to rollerblade on shabbas? Do we compare it to biking (Kaf Hachaim assurs it)? Are there any contemporary tshuvos which discuss this? I have heard two problems if ...
In SA OC Siman 340 in the Taz Sif-Katan 1 and brought in M"B Sif-Katan 10 that one shouldn't remove wax from on top of an ois (letter) in a Sefer because of the issur of "erasing" (mechika). The Biur ...