ich wuerde hier einfach "..., i.e. f is ..." nehmen

I have observed that some authors insert a comma after e.g. and i.e. and some do not. What is correct?
Some journals use American English, while some use British English. In the American style of writing, a comma is inserted before and after i.e. and e.g. However, in the British style of writing, a comma is inserted before but not after these abbreviations.
http://blog.editage.com/?q=taxonomy/term/345

Is there a comma after ie in a sentence?
Answer
The abbreviation "i.e.," which stands for the Latin phrase id est--"that is"--is written with lowercase letters and a period after each, and no space in between.
When you use it in a sentence to signify "that is," you do follow it with a comma:
* Jacob held the highest office in the club; i.e., that of president.
* The process of electrolysis breaks water down into its components; i.e., hydrogen and oxygen.
http://wiki.answers.com/Q/Is_there_a_comma_af...

Hier ein paar schnell ergoogelte Regeln.

Thanks for your answers. But I do want to use "that is" and not "i.e.". So it would be great if someone knows the rule in that case...

Yes, there's a comma after "that is".

I always use a comma before and after "that is". For me it would be incorrect to omit either.



[[Chicago Manual of Style recommends a comma after "i.e.", Oxford Guide to Style discourages it.]]

I'd put a semi-colon before it and a comma after it in this case. With another "is" coming so soon after, you really need a comma to make it clear.

Awesome, this means I don't need to correct it everywhere in my thesis :)
And thanks also because www.chicagomanualofstyle.org seems to explain everything I need to know.

IMHO, you don't need it after "i.e." at all, as it tends to just clutter up the text with lots of (unnecessary) punctuation - which tends NOT to aid readability.

You want one before the i.e., but unless there's a reason (like in this sentence) that you need a comma after it, I'd personally ditch it. If however it is necessary to make the meaning of a sentence clear, by all means leave it there.

You don't see people writing a comma after "e.g." either, although you'd put one after "for example".

In your case, as you're writing "that is" or "for example" in full, you generally will need the comma, and in this case it makes your example text much easier to read. A missing comma can sometimes radically change the meaning of a sentence or make it harder for people to understand the sentence the first time they read it.

@#8: You don't see people writing a comma after "e.g."

As with "i.e." (see #5) you do if you follow CMS recommendations: "A comma is usually used after such expressions as that is, namely, i.e., and e.g." (Chicago Manual of Style, §5.62)

The comma after "e.g." is used in the US:

"In OUP style 'e.g.' and 'i.e.' are not followed by commas, to avoid double punctuation; commas are often used in US practice." (OMS)