+* YAZ now auto-generates decoders/encoders for the Z39.50 protocol using
+a fairly small ASN.1 compiler written in Tcl. The compiler is located
+in util/yc.tcl. The auto-generated C code structures are, in a few
+cases, incompatible with the old decoders. There are differences in the
+following C structures Z_DiagRec, Z_External, Z_SortRequest, Z_SortResponse,
+Z_AttributesPlusTerm, Z_ProximityOperator, Z_DefaultDiagFormat.
+The preprocessor variable ASN_COMPILED is defined when the compiled
+ASN.1 is being used. Encoder/decoder routines as well as the Z39.50
+protocol ASN.1 is located sub directory <tt>z39.50</tt>. If you
+wish to use the old encoders/decoders you can specify --disable-yc
+for configure.
+