\DeclareFontEncodingDefaults {<text-settings>} {<math-settings>}
Declares <text-settings> and <math-settings> for all encoding
schemes. These are executed before the encoding scheme dependent ones
are executed so that one can use the defaults for the major cases and
overwrite them if necessary using \DeclareFontEncoding.
If \relax is used as an argument, the current setting of this default
is left unchanged.
This example is used by amsfonts.sty for accent positioning; it changes
only the math settings:
\DeclareFontEncodingDefaults{\relax}{\def\accentclass@{7}}
\DeclareFontSubstitution {<encoding>} {<family>} {<series>}
{<shape>}
Declares the default values for font substitution which will be used
when a font with encoding <encoding>
should be loaded but no font can be found with the current
attributes.
These substitutions are local to the encoding scheme because the
encoding scheme is never substituted! They are tried in the order
<shape> then <series> and finally <family>.
If no defaults are set up for an encoding, the values given by
\DeclareErrorFont are used.
The font specification for
<encoding><family><series><shape>
must have been defined by \DeclareFontShape
before the \begin{document} is reached.
Example:
\DeclareFontSubstitution{T1}{cmr}{m}{n}