PHP constants are defined using <constant> tags.
The actual constant name, type and value are specified using the
name, type and value attributes. Valid types for a constant
are int, float and string.
For int and float you may use either numeric strings or the
names of C constants (either true ANSI C/C++ constants or values
#defined using the C preprocessor. string values
are always used "as is", no constants may be used here.
If only the name attribute is given it is assumed that the
constant is supposed of type int and that its value is to be
that of a C constant of the same name.
A descriptive text may be given as data content of the
<constant> tag. This text will be used
when generation the DocBook XML documentation.
<constant name="ANSWER" type="int" value="42">Answer to THE question</constant>
<constant name="PI" type="float" value="3.14"/>
<constant name="MYNAME" type="string" value="Hartmut Holzgraefe"/>
<constant name="FOOBAR" type="int" value="FOOBAR"/>
<constant name="FOOBAR"/> <!-- short form of previous constant -->
