The Elements of Style

In the names of business firms the last comma is omitted, as

Brown, Shipley and Company

The abbreviation etc.,

Exceptions are the possessives of ancient proper names in -es and -is, the possessive Jesus' , and such forms as for conscience' sake, for righteousness' sake. But such forms as Achilles' heel, Moses' laws, Isis' temple are commonly replaced by

the heel of Achilles

the laws of Moses

the temple of Isis

The pronominal possessives hers, its, theirs, yours, and oneself have no apostrophe.

he abbreviation etc., even if only a single term comes before it, is always preceded by a comma.

The Elements of Style

The abbreviations etc. and jr. are always preceded by a comma, and except at the end of a sentence, followed by one.

The man whom he thought was his friend
The man who (that) he thought was his friend (whom he thought his friend)

Compare:

While the temperature reaches 90 or 95 degrees in the daytime, the nights are often chilly.

Although the temperature reaches 90 or 95 degrees in the daytime, the nights are often chilly.

The paraphrase,

The temperature reaches 90 or 95 degrees in the daytime; at the same time the nights are often chilly,

shows why the use of while is incorrect.

In general, the writer will do well to use while only with strict literalness, in the sense of during the time that.

While.

Avoid the indiscriminate use of this word for and, but, and although. Many writers use it frequently as a substitute for and or but, either from a mere desire to vary the connective, or from uncertainty which of the two connectives is the more appropriate. In this use it is best replaced by a semicolon.

each, each one, everybody,every one, many a man, which, though implying more than one person, requires the pronoun to be in the singular.

One of the most.

Avoid beginning essays or paragraphs with this formula, as, "One of the most interesting developments of modern science is, etc.;" "Switzerland is one of the most interesting countries of Europe." There is nothing wrong in this; it is simply threadbare and forcible-feeble.