# Using cls file - “the document class provides book'.”

I am co-writing a book and I've been sent the publishers LaTeX template which contains their style files. At first I was getting the error ietbook.cls file not found - the following seemed to be the error:

\documentclass[10pt]{ietbook}

The file name was:

IETBook.cls

After I have changed this to:

\documentclass[10pt]{IETBook}

I am now getting the following warnings (The compiled file is clearly wrong in format):

./IETBook.cls: LaTeX Warning: You have requested document class IETBook', but the document class provides book'.
./fleqn.sty: LaTeX Warning: inputting fleqn.clo' instead of obsolete fleqn.sty'.
./IETBook.cls:765: Package crop Warning: Requested option ' not provided on input line 765.

What could be causing this issue?

EDIT: Line referred to in third warning:

\if@cropmarkson \crop[cam,info] \fi

• They all seem to be errors in the class file provided by the publisher. Complain to them.... – David Carlisle Apr 15 '15 at 8:24
• Before I complain is the error regarding fleqn.sty ignorable or does it also look like a serious issue? – Colin747 Apr 15 '15 at 9:11
• It's ignorable as in latex does fix it but fleqn.sty has been obsolete and replaced by fleqn.clo since 1994. They have had time to make the one line change required by now.... – David Carlisle Apr 15 '15 at 9:17
• Thanks for your input, hopefully I was just sent an archived template by mistake. – Colin747 Apr 15 '15 at 9:18

This means that the class file is IETBook.cls but has the line

\ProvidesClass{book}

presumably just copied without thought from the standard book class.

Or possibly it uses

\input{book.cls}