So, in my curiosity, I wanted to know what those numbers meant. I had always heard about reusing only the good bottles and other folk-lorish warnings. So what do those numbers mean?

Plastic bottles didn’t gain much speed until the 1960s. Their popularity made manufacturers turn to different methods of construction. In 1988 the Society of Plastics Industry developed a Resin Identification Code to show consumers what type of plastic they were purchasing.

Each number obviously corosponds to a particular polimer. Rather than get into the specific chemical makeup of each substance, what does this mean to the consumer? How should we treat each type, and what should we avoid? Here is the lowdown.

The Good Ones
1 (This is what most water and coke bottles are made out of), 2, 4, 5

The Bad Ones
3, 6, 7

Really you want to avoid some because of the chemicals they can release into your water. Also, if your water smells or tastes funny after reusing a water bottle, then it is probably time to replace your bottle. Look at the bottom of the next bottle you drink out of and see what it says.

This is a slang term and much of the definition is derived from the Urban Dictionary. It originated in the late 80’s on the west coast.

po•po [poh-poh] –noun
Police Officer, particularly those traveling by bicycle

Police officers used to wear vests bearing the large block letters “PO”, standing for police officer. Traveling in pairs, standers by saw the word POPO when they stood next to each other. Thus the slang word for police was birthed. See example below.

After hearing my colleague employ the word throughout the day I had to visit the dictionary to verify both meaning, spelling and existence.  Bellicosity is the adverbial form from the word bellicose.

bel·li·cose  [bel-i-kohs] –adjective
inclined or eager to fight; aggressively hostile; belligerent; pugnacious.

The best usage can be found circa second 50 of the video below.