At:   http://apr.apache.org/docs/apr/1.3/group__apr__platform.html

The Doxygen documentation says:

#define APR_DECLARE_DATA

The public APR variables are declared with AP_MODULE_DECLARE_DATA. This assures the appropriate indirection is invoked at compile time.

See also:
    APR_DECLARE

    APR_DECLARE_NONSTD

Remarks:
    Note that the declaration and implementations use different forms, but both must include the macro.

 extern APR_DECLARE_DATA type apr_variable;


 APR_DECLARE_DATA type apr_variable = value;

 
I suspect that the reference to AP_MODULE_DECLARE_DATA is a relic from a previous naming convention.  It certainly is confusing if that is not the explanation, since the examples then do not tie up with text.

--
Jonathan Leffler <jonathan.leffler@gmail.com> #include <disclaimer.h>
Guardian of DBD::Informix - v2008.0513 - http://dbi.perl.org
"Blessed are we who can laugh at ourselves, for we shall never cease to be amused."