\begingroup \catcode"C3=\active \catcode"C5=\active % \def^^c3#1{% \ifx#1^^a6^^1a\else % æ - U+00E6 - ae \errmessage{Hyphenation pattern file corrupted or OT1 encoding not supported!} \fi} \def^^c5#1{% \ifx#1^^93^^1b\else % œ - U+0153 - oe \errmessage{Hyphenation pattern file corrupted or OT1 encoding not supported!} \fi} % % ensure all the chars above have valid lccode values % \lccode"1A="1A % æ - U+00E6 - ae \lccode"1B="1B % œ - U+0153 - oe % Ligatures ae and oe (in OT1) \patterns{ æ1 œ1 } \endgroup