\ClassError and \PackageError and other messages ¶Produce error, warning, and informational messages for classes:
\ClassError{class name}{error-text}{help-text} ¶\ClassWarning{class name}{warning-text}\ClassWarningNoLine{class name}{warning-text}\ClassNote{class name}{note-text}\ClassNoteNoLine{class name}{note-text}\ClassInfo{class name}{log-text}and the same for packages:
\PackageError{package name}{error-text}{help-text} ¶\PackageWarning{package name}{warning-text}\PackageWarningNoLine{package name}{warning-text}\PackageNote{package name}{note-text}\PackageNoteNoLine{package name}{note-text}\PackageInfo{package name}{log-text}For \ClassError and \PackageError the message is
error-text, followed by TeX’s ‘?’ error prompt. If the
user then asks for help by typing h, they see help-text.
The four Warning commands write warning-text on the
terminal and log file (with no error prompt), prefixed by the text
‘Warning:’.
The four Note commands also write the note-text to the
terminal and log file, without the ‘Warning:’ prefix.
The NoLine versions omit the number of the input line
generating the message, while the other versions do show that number.
The two Info commands write log-text only in the
transcript file and not to the terminal.
To format the messages, including the help-text: use
\protect to stop a command from expanding, get a line break
with \MessageBreak, and get a space with \space where a
space character is ignored, most commonly after a command.
LaTeX appends a period to the messages.