# Redefine \textsc for slightly large small caps

In most fonts, the small caps are as tall as the x-height, but this looks weird when you want to tack an 's' onto the end of an abbreviation to make it plural (discussed in depth on typophile).

I can create a new command `\textmc` (for moyen caps) to do this easily:

``````\usepackage{scalefnt}
\newcommand{\textmc}[1]{\textsc{\scalefont{1.1}#1}}
``````

But I'd prefer to just redefine `\textsc`. The approach that I was taking, however, seems to give me an infinite loop as it flips back and forth between defintions:

``````\newcommand{\oldtextsc}[1]{\textsc{#1}}
\renewcommand{\textsc}[1]{\oldtextsc{\scalefont{1.1}#1}}
``````

Any advice on how to redefine a command which calls the original definition?

-

A straightforward way is to use `\let` to store the current definition of `\textsc`.

``````\let\oldtextsc\textsc
\renewcommand{\textsc}[1]{\oldtextsc{\scalefont{1.1}#1}}
``````

(See Patching existing commands from the UK TeX FAQ for details.)

However, this can fail if `\textsc` happens to be in some place that gets written in the aux file (a section title, for instance), so a safer version is

``````\usepackage{letltxmacro}
\LetLtxMacro{\oldtextsc}{\textsc}
\renewcommand{\textsc}[1]{\oldtextsc{\scalefont{1.1}#1}}
``````

(see the documentation of `letltxmacro` for more information).

The problem is that `\textsc` is a "robusted" command, so that LaTeX will write a special form of it in the aux file; something like `\section{\textsc{a}}` would result in LaTeX writing

``````\textsc  {\scalefont  {1.1}a}
``````

and when interpreting it for the table of contents this would become

``````\oldtextsc{\scalefont{1.1}\scalefont{1.1}a}
``````

and eventually to a scaling factor of 1.21.

-
There is a problem in this redefinition if `\textsc` happens to be written in the `.aux` file: `\textsc{a}` would become `\textsc{\scalefont{1.1}a}` which would result in a scaling factor of 1.21. –  egreg Mar 17 '12 at 14:36
@egreg My answer was mainly about `\let` and didn't touch the substance of the OP's definition. Please point out any changes needed (or feel free to edit my answer). –  lockstep Mar 17 '12 at 14:40