titleModes (class TitleModes)
               Tells xterm whether to accept or return window‐ and icon‐labels
               in ISO‐8859‐1 (the default) or UTF‐8.  Either can be encoded in
               hexadecimal.  The default for this resource is “0.”

               Each  bit  (bit "0" is 1, bit "1" is 2, etc) corresponds to one
               of the parameters set by the title modes control sequence:

               0    Set window/icon labels using hexadecimal

               1    Query window/icon labels using hexadecimal

               2    Set window/icon labels using UTF‐8  (overrides  utf8Titles
                    resource).

               3    Query window/icon labels using UTF‐8