ANSI Common Lisp 1 Introduction
1.8 Deprecated Language Features
Deprecated language features are not expected to appear in future Common Lisp standards, but are required to be implemented for conformance with this
standard; see Section 18.104.22.168 Required Language Features.
Conforming programs can use deprecated features;
however, it is considered good programming style to avoid them.
It is permissible for the compiler to produce style warnings
about the use of such features at compile time,
but there should be no such warnings at program execution time.
1.8.1 Deprecated Functions
1.8.2 Deprecated Argument Conventions
1.8.3 Deprecated Variables
1.8.4 Deprecated Reader Syntax