Rebel:

Also, you should know that floor tiles are set individually, and by hand, and so it's normal for them to not all be exactly the same height. Most of the time that's not a problem because the elevation differences aren't enough to trip over. But, they can be enough to cause a toilet bowl to rock a little.

Consequently, it's common for tile setters to jam coins under the toilet bowl to prevent that rocking OR caulk around the base of the bowl to minimize movement of the bowl. The caulk around the front of your bowl was very possibly put there by the people who tiled the floor to prevent the bowl from rocking.

Really, the place to caulk is around the toilet floor flange and to caulk up any holes in the floor flange itself. That way, if your wax seal leaks, the water won't leak into the floor to cause wood rot or water damage to the ceiling below. It'll leak out onto the floor beside the toilet to alert you of a leaking wax seal.

A caulk called Kop-R-Lastic sticks well to both ABS and PVC floor flanges. Both Kop-R-Lastic and Stone Mason Gutter & Siding Sealant are exactly the same caulk being sold in different tubes by the same manufacturer. In Canada, both products are made by the U.S.E. Hickson Company and in the US, both are made by the Henrys company. In Canada, Home Depot sells Stone Mason Gutter & Siding Sealant, but only in the area of the store where they sell evestroughing materials; not in their painting area. Also, Kop-R-Lastic can be ordered in about 10 different colours, but Home Depot only sells Stone Mason Gutter & Siding Sealant in white and clear. Use this stuff to caulk around your toilet floor flange the next time you take the toilet off.

Stone Mason Gutter & Siding Sealant is my favouritest caulk. It sticks well right away, so that it has good ADhesion to building materials, but over the course of the next three to five years, the synthetic rubber molecules in it crosslink with each other, making it a bit stiffer, but raising it's COhesive strength above it's adhesive strength. That means it sticks to itself even better than it sticks to common construction materials. That's a real advantage because if you ever want to remove the stuff, you just get one end of it started, and it pulls off like a rubber rope. It is hard to pull it off, but it pulls off cleanly, making the job of re-caulking very much faster and easier because completely removing the old caulk only takes a minute. I won't use any other caulk on the 66 windows in my building because with this stuff, insufficient adhesion is never a problem, but removing it when you want/need to is a breeze.