Copyright (C) Caldera International Inc. 2001-2002. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

Redistributions of source code and documentation must retain the above
copyright notice, this list of conditions and the following
disclaimer.

Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.

All advertising materials mentioning features or use of this software
must display the following acknowledgement:

This product includes software developed or owned by Caldera
International, Inc. Neither the name of Caldera International, Inc.
nor the names of other contributors may be used to endorse or promote
products derived from this software without specific prior written
permission.

USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE
FOR ANY DIRECT, INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
OR OTHERWISE) RISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
@(#)ssd 8.1 (Berkeley) 6/8/93

$FreeBSD$
Appendix D: Old Features Supported but not Encouraged

This Appendix mentions synonyms and features which are supported for historical continuity, but, for various reasons, are not encouraged.

1.
Literals may also be delimited by double quotes ``"''.
2.
Literals may be more than one character long. If all the characters are alphabetic, numeric, or \_, the type number of the literal is defined, just as if the literal did not have the quotes around it. Otherwise, it is difficult to find the value for such literals.
The use of multi-character literals is likely to mislead those unfamiliar with Yacc, since it suggests that Yacc is doing a job which must be actually done by the lexical analyzer.
3.
Most places where % is legal, backslash ``\e'' may be used. In particular, \e\e is the same as %%, \eleft the same as %left, etc.
4.
There are a number of other synonyms: %< is the same as %left %> is the same as %right %binary and %2 are the same as %nonassoc %0 and %term are the same as %token %= is the same as %prec
5.
Actions may also have the form ={ . . . } and the curly braces can be dropped if the action is a single C statement.
6.
C code between %{ and %} used to be permitted at the head of the rules section, as well as in the declaration section.