I summarize here some of the style guidelines I like to follow when coauthoring papers. 
These guidelines are addressed primarily to my students. 
I almost invariably use Latex, so the guidelines refer to that. 

== How to Collaborate ==

I use an svn repository for collaboration (I moved from cvs to svn).  A paper started in 2006 will be in {{{https://dvlab.cse.ucsc.edu/svn/06-papernickname}}}, and to get it, you should do: 
{{{
  svn co https://dvlab.cse.ucsc.edu/svn/06-papernickname }}}
Typically, only people involved with the papers have access to the repositories. 
In the repository, there are generally the following subdirectories: 
 * '''Workspace''' - this is were the initial draft is kept
 * '''FOO06''' - this is the version submitted to FOO06
and so forth.  In each directory, the main file is called {{{main.tex}}}, and you can process it via 
{{{
  latex main.tex }}}
Sometimes, there is also a web-ready version in the directory, where the first page says where the paper appeared.  This is the version of the paper that I put on the web.  The version, if present, is called {{{main-web.tex}}}. 
Please check in all files required to construct the paper, but unless there is a special reason, do not check in the postscript and pdf files generated from the paper. 

=== Useful Stylefiles ===

 * {{{dvlab.bib}}}, available from {{{https://dvlab.cse.ucsc.edu/svn/bib}}}, contains most of the citations I use.  Check it out, then make a symbolic link from it to the directory when you use it. 
 * {{{luca.sty}}} is a stylefile I almost invariably like to use.  You can find it in {{{https://dvlab.cse.ucsc.edu/svn/sty}}}. 

== Paper Format ==

=== Text Formatting ===

 * '''Keep the text width to less than 80 columns.'''  I like to keep two editor windows open side-to-side on the paper, and it's difficult if the lines are wider.  
 * '''Please start every new sentence on a new line.''' That is, '''don't ever reflow paragraphs.''' I know it sounds like a pain at the beginning, but it makes it much easier to move text around, locate sentences in paragraphs, and judge by eyeball how long sentences are.  I have an ["Emacs fill-sentence"] macro that can help you to reflow a sentence, without reflowing the whole paragraph. 
 * '''Try not to break math formulas across lines''' if possible. 
 * '''Leave some space around math operators''', and write for example {{{$\bigcup \set{r | r \in R} = S$}}} rather than {{{$\bigcup\set{r|r\in R}=S$}}}.  For small formulas, it is acceptable to remove some space, for instance, {{{$(v+u)(s) = v(s) + u(s)$}}} is quite readable.  Use your judgement, keeping ease of reading as the goal.
 * '''Please leave blank lines above and below section titles.''' 
 * '''Please use indentation for math and itemizations.'''
 * Use {{{%}}} to separate portions of text in the editor, without causing a change of paragraph.  For instance: {{{
Given a subset $T \subs S$ of states, the reachability goal $\Diamond T$
consists in the paths reaching $T$, and the safety goal $\Box T$
consists in the paths that stay always in $T$:
%
\begin{align*}
  \Diamond T & = \set{\overline{s} \in \Omega \mid \exists k. \overline{s}_k \in T} &
  \Box T     & = \set{\overline{s} \in \Omega \mid \forall k. \overline{s}_k \in T}
\end{align*}
%
These sets of paths are measurable, so that given a ...}}}
 The single {{{%}}} above are used to leave visual space in the editor around the displayed equation, without causing a change of paragraph in the Latex.  This example also shows some typical macros I use ({{{\set}}}, {{{\subs}}}), and the use of the {{{align}}} environment, which I prefer to {{{eqnarray}}}.


=== Macro Usage ===
 
Please consider using macros for many of the non-obvious symbols and notation, so we can change notation midway through the paper.  Call the macro file {{{macro.sty}}}, and include it from {{{main.tex}}}. Keep your macros informative but short. 

=== Labels ===

Use labels of the form {{{\label{def-game} }}}. 
Two things are to notice: 
 * The label name has a first part, "def", which specifies that it is a definition.  Typical first parts are: def, theo, lem, algo, fig, tab. 
 * The first part of the label name is separated from the rest with "-".  Many people use ":" instead, but "-" is better: emacs does not consider "-" to be a word separator (unlike ":"), so that automatic word completion (M-/) enables me to quickly complete (and, more importantly, guess) the labels. 

== Macros ==

Here are some of the macros that I would really like students to follow. 
They are defined in {{{luca.sty}}} (see above). 

|| '''Macro''' || '''Meaning''' ||
|| \union || \cup {1} ||
|| \inters || \cap {1} ||
|| \setm || \setminus ||
|| \subs || \subseteq ||
|| \und || \wedge {1} ||
|| \oder || \vee {1} ||
|| \im || \rightarrow ||
|| \no || \neg ||
|| \sat || \models ||
|| \set{...} || \{ ... \} ||
|| \sem{...} || [[ ... ]] ||
|| \bo || Box, the temporal operator ||
|| \diam || Diamond, the temporal operator ||
|| \until || Until, the temporal operator ||

{1} I always confuse \cup, \cap, \vee, \wedge, so I use these macros. 

Also, note the following suggestions: 

 * The following macros work in Latex, and they should be used to get parentheses of the appropriate sizes: {{{\bigl, \biggl, \Bigl, \Biggl}}}. 
 * Please don't write {{{$Cpre(X)$}}}: the spacing around the letters "Cpre" would be all wrong.  Please take the time to write {{{$\text{\textrm{Cpre}}(X)$}}}, or better, define a macro. 
 * If you do define macros, please keep their names short, and preferably in all lowercase, otherwise, it is very cumbersome to write the paper. 
 * Do not define macros for things that have standard names, such as {{{s}}} for a state.