The font shape declarations in this description are taken out of order for clarity of explanation; in the actual file generated, the font shape declarations are in a different order. Note the order of font shape declarations does not matter in a .fd file.

% Autogenerated by ./otftex_install.py on 2005/06/27
\ProvidesFile{ly1pacx.fd}[2005/06/27 LY1/ACaslonPro] Announces the name of the file with a long description

\DeclareFontFamily{LY1}{pacx}{}
Indicates the font family "pacx" is available in the encoding scheme "LY1".

\DeclareFontShape{LY1}{pacx}{m}{n}{
<-> LY1-ACaslonPro-Regular-kern-liga
}{}
For the font family "pacx", encoded in the encoding "LY1", what font file has the characteristics of series "m" ("medium") and shape "n" ("normal" [upright])? Answer: "LY1-ACaslonPro-Regular-kern-liga". The "<->" means "all sizes" (for specific point sizes from n to m, it would be "<n-m>"). Note that these names have to correspond to the font filenames generated by the font installation script. In this case, the filenames use long filenames (not Berry).

\DeclareFontShape{LY1}{pacx}{m}{sc}{
<-> LY1-ACaslonPro-Regular-kern-liga-smcp
}{}
\DeclareFontShape{LY1}{pacx}{m}{sl}{
<-> sub * pac/m/it
}{}
\DeclareFontShape{LY1}{pacx}{m}{it}{
<-> LY1-ACaslonPro-Italic-kern-liga
}{}
Same question, but with shapes "it" (italic), "sl" (slanted), and and "sc" (small caps). Note that we did not generate a "slanted" variant, so instead we are asking LaTeX to "sub"stitute the italic variant if it needs the slanted one.

\DeclareFontShape{LY1}{pacx}{b}{sc}{
<-> LY1-ACaslonPro-Bold-kern-liga-smcp
}{}
\DeclareFontShape{LY1}{pacx}{b}{sl}{
<-> sub * pac/b/it
}{}
\DeclareFontShape{LY1}{pacx}{b}{it}{
<-> LY1-ACaslonPro-BoldItalic-kern-liga
}{}
\DeclareFontShape{LY1}{pacx}{b}{n}{
<-> LY1-ACaslonPro-Bold-kern-liga
}{}
How about the series "b" (bold)?

\DeclareFontShape{LY1}{pacx}{sb}{sc}{
<-> LY1-ACaslonPro-Semibold-kern-liga-smcp
}{}
\DeclareFontShape{LY1}{pacx}{sb}{sl}{
<-> sub * pac/sb/it
}{}
\DeclareFontShape{LY1}{pacx}{sb}{it}{
<-> LY1-ACaslonPro-SemiboldItalic-kern-liga
}{}
\DeclareFontShape{LY1}{pacx}{sb}{n}{
<-> LY1-ACaslonPro-Semibold-kern-liga
}{}
How about the series "sb" (semibold)?

\DeclareFontShape{LY1}{pacx}{bx}{sc}{
<-> sub * pac/b/sc
}{}
\DeclareFontShape{LY1}{pacx}{bx}{sl}{
<-> sub * pac/bx/it
}{}
\DeclareFontShape{LY1}{pacx}{bx}{it}{
<-> sub * pac/b/it
}{}
\DeclareFontShape{LY1}{pacx}{bx}{n}{
<-> sub * pac/b/n
}{}
And finally, how about the series "bx" (bold extended)? Well, in this case, we don't have a bold extended font source file. So instead we say that we can substitute bold ("pacx/b/") for bold extended.

\endinput