The documentation for mod_macro under Tips:

    https://httpd.apache.org/docs/2.4/mod/mod_macro.html#tips

provides an example using the ${...} syntax for macro arguments.  Attemping to use
this in an actual Apache configuration:

    <Macro VHost ${domain} ${suffix} ${dir}>
        <VirtualHost *:80>
            ServerName  www.${domain}.${suffix}
            ServerAlias ${domain}.${suffix}
            # ...
            ErrorLog ${APACHE_LOG_DIR}/${domain}.${suffix}-error.log
            CustomLog ${APACHE_LOG_DIR}/${domain}.${suffix}-access.log combined
        </VirtualHost>
        # ...
    </Macro>

results in a few occurrences of the following warning:

    [macro:warn] [pid 29527] AH02805: macro 'vhost' (defined on line 5 of "/etc/apache2/sites-enabled/100-macro-sites.conf") argument name '${domain}' (#1) clashes with 'Define' syntax '${...}', better use '$(...)'.

Fixing all occurrences of ${...} to use the $(...) syntax, **except** for things like ${APACHE_LOG_DIR}, silences the warning.

Documentation should be modified to use the $(...) syntax instead of ${...} syntax for macro arguments, including in the <Macro> line.