# What is “\\” called?

I’ve seen it take arguments, and apparently there’s a starred version, but I can’t find any documentation because it is ungooglable!

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See section 10.1, page 36, in the unofficial reference manual (texdoc latex2e). The definition is probably different depending on where it's used (tables, multi-line math, text). – Torbjørn T. Aug 14 '12 at 17:59
perhaps you can google "latex double backslash" ? – Corentin Aug 14 '12 at 18:01
I would call it a line-breaking command. Its definition may vary according to the context it's used in, but its essential purpose is to force a line break. – Mico Aug 14 '12 at 18:11
As another example where the meaning is different take tex.stackexchange.com/questions/65683/… – in listings options you can use it as an escaped backslash. – canaaerus Aug 14 '12 at 20:13

There is no official name for it (at least I don't know of any) and it would be difficult to give it a single short name as the purpose of this command is more or less

A command to separate lines or rows of material (depending on context) while controlling the space between such lines or rows and indicating whether a page break between them is forbidden.

Now turn this into a short word please :-)

The full syntax in standard LaTeX is \\*[dimension] with the * indicating that a pagebreak is forbidden (it may not be allowed anyway for other reasons) and the dimension defining the extra space to be added between the two rows or lines. Both the *and the [...] are optional and it is allowed to put spaces between \\ and * and [...].

This is what all environments etc of standard LaTeX use when they make use of this command. The actual code that the command runs depends on the situation, so in a tabular it technically does something completely different to the situation in a paragraph. See also What does \\* do?

An introduction such as ltshort will cover this command in detail, along with other ungooglable terms.

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I would call \\ a row delimiter, and \\* a non-breaking one. – Jon Purdy Aug 15 '12 at 0:02
@JonPurdy in most cases it is not a delimiter, but a separater, for example it should not be used at the end of a paragraph. – Frank Mittelbach Aug 15 '12 at 7:03
@FrankMittelbach I hate using \ because of that. It drives me nuts when I try to break something and get an ERROR! because I used it at the end of a hidden par. Is there any way to redefine \ so it work sat the end of a par(possibly doing nothing)? – AbstractDissonance Aug 15 '12 at 22:26
@AbstractDissonance it isn't really a bad thing if you hate \\. If you feel that you need to use it often in running text (not tabular or so) then you are doing something wrong (not thinking of LaTeX as a way to separate content from form). – Frank Mittelbach Aug 16 '12 at 21:27
@FrankMittelbach Possibly but in many cases it is the quickest way to do the job and I see no reason why \ should cause an error since it is not fatal. I'm not always looking to do things right... sometimes I just want to get it done the quickest and easiest way I know how. – AbstractDissonance Aug 17 '12 at 5:40

\\ has no official name, but is often called the line-breaking command. Searching the web for “latex line-breaking command” turns up useful info as the top result.

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This look more like a comment than an answer, in the current form. One of the moderators will most likely convert it after a short delay. – Joseph Wright Aug 15 '12 at 7:05
My question was how to google it, and this is the best answer. – andrew Aug 15 '12 at 7:15
As written, the question to me seems to ask for information about \\ , rather than how to Google for information about \\ . The latter question would in any case be better suited to SuperUser, where I expect some complex escape string would be given as an answer. – Joseph Wright Aug 15 '12 at 7:26
You can’t search for it here on tex.sx either, but there is a “line-breaking” tag, and searching for “line-breaking” turns up useful results while “\\” does not. So I think that the answer is to call it the line-breaking command. – andrew Aug 15 '12 at 7:31
A better fitting answer would be something like "\\ is called a line breaking command", but not which keywords to use for getting best google results. Perhaps you like to edit it? – Stefan Kottwitz Aug 15 '12 at 14:58