UK TeX FAQ -- question label casechange

### Case-changing oddities

TeX provides two primitive commands `\``uppercase` and `\``lowercase` to change the case of text; they're not much used, but are capable creating confusion.

The two commands do not expand the text that is their parameter - the result of `\``uppercase{abc}` is '`ABC`', but `\``uppercase{`\``abc`}` is always '`\``abc`', whatever the meaning of `\``abc`. The commands are simply interpreting a table of equivalences between upper- and lowercase characters. They have (for example) no mathematical sense, and

>     \uppercase{About $y=f(x)$}

will produce

>     ABOUT $Y=F(X)$

which is probably not what is wanted.

In addition, `\``uppercase` and `\``lowercase` do not deal very well with non-American characters, for example `\``uppercase{`\``ae`}` is the same as `\``ae`.

LaTeX provides commands `\``MakeUppercase` and `\``MakeLowercase` which fixes the latter problem. These commands are used in the standard classes to produce upper case running heads for chapters and sections.

Unfortunately `\``MakeUppercase` and `\``MakeLowercase` do not solve the other problems with `\``uppercase`, so for example a section title containing `\``begin{tabular}` ... `\``end{tabular}` will produce a running head containing `\``begin{TABULAR}`. The simplest solution to this problem is using a user-defined command, for example:

>     \newcommand{\mytable}{\begin{tabular}...
>       \end{tabular}}
>     \section{A section title \protect\mytable{}
>       with a table}

Note that `\``mytable` has to be protected, otherwise it will be expanded and made upper case; you can achieve the same result by declaring it with `\``DeclareRobustCommand`, in which case the `\``protect` won't be necessary.

David Carlisle's textcase package addresses many of these problems in a transparent way. It defines commands `\``MakeTextUppercase` and `\``MakeTextLowercase` which do upper- or lowercase, with the fancier features of the LaTeX standard `\``Make*`-commands but without the problems mentioned above. Load the package with `\``usepackage[overload]{textcase}`, and it will redefine the LaTeX commands (not the TeX primitive commands `\``uppercase` and `\``lowercase`), so that section headings and the like don't produce broken page headings.

`textcase.sty`
  Distributed as part of macros/latex/contrib/carlisle (zip, browse)

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