On machine-made bottles additional markings can be the product of the automated machinery which produce the bottle, but which are not part of the mold itself.Most significant here are markings related to the feeding of the glass to the mold - a subject covered later on this page in the "Machine-made bottles" section.: The bases of many bottles have embossing or symbols that pertain to the product that the bottle was designed to contain and/or the producer or bottler of the product.
There is also large section on pontil marks or scars due to its size (hyperlink found several places below).
Short differentiating informational statements are provided below (in bold) to make an easy "break" between mouth-blown and machine-made bottles.
Mouth-blown bottles - Mouth-blown bottles have a side mold seam which terminates on the neck or within the finish (lip) below the top of the bottle; or less frequently, have no apparent side mold seams.
All mouth-blown bottles have in common the fact that they were blown with the force of a glassblowers lungs, not mechanically by machine.
These are usually some type of embossed letters, symbols, and/or numbers which were molded onto the base of the bottle for a variety of glassmaker determined reasons.