"Font shape undefined" with latex and isodoc

Question

I'm trying to create a simple invoice with pdflatex and the isodoc class. Unfortunately, the "INVOICE" opening is appear in all lowercase, and I suspect this warning is the reason why:

LaTeX Font Warning: Font shape `T1/lmr/bx/sc' undefined
(Font)              using `T1/lmr/bx/n' instead on input line 19.

My best guess at this cryptic output is that latex doesn't know how to represent small caps. What can I do to teach it how?

Here is the preamble of my document:

\documentclass{isodoc}
\usepackage[latin1]{inputenc}
\usepackage[T1]{fontenc}

The system is Fedora Core 4 . pdflatex -version yields:

pdfeTeX 3.141592-1.21a-2.2 (Web2C 7.5.4)
kpathsea version 3.5.4

And:

$ rpm -qa | grep tex
tetex-dvips-3.0-10.FC4
tetex-fonts-3.0-10.FC4
tetex-3.0-10.FC4
tetex-latex-3.0-10.FC4
passivetex-1.25-5
gettext-0.14.3-1
xmltex-20020625-5.2
texinfo-4.8-8.fc4.2

Answer 1

I managed to partially work around this by altering the invoice text. I found it defined in the isodoc source with:

\def\invoicetext{{\bfseries\Large\scshape invoice}}

Adding the following after my document setup removed the use of small capitals:

\def\invoicetext{{\bfseries INVOICE}}

Answer 2

The error/warning is fairly self explanatory if you know what to look at.

T1/lmr/bx/sc refers to a specific font declaration:

T1 — so-called ‘Cork’ font encoding
lmr — ‘Latin Modern Roman’ font family
bx — bold
sc — small caps

By saying this font shape is "undefined" simply means that the Latin Modern Roman doesn't have bold small caps. As a fall-back, the default bold font is chosen instead.

As you've now discovered, not writing \bfseries\scshape in the first place will resolve the warning :)