This is a best practices document, its aims is to help implementors handling this technique and it may evolve over time.
The related section of the specification is TDM Header Field in HTTP Responses.
HTTP headers can easily be integrated by web servers like Apache (using mod_headers), reverse-proxies like nginx, or directly in the source code driving the behavior of a web server (e.g. using Golang). This is made particularly easy if the resources associated with given TDM properties are placed in specific locations.
In Apache for instance, setting TDM-a to 0 for all resources contained in the directory "/path" is obtained via the directive:
<Directory "/path">
Header set TDM-a "0"
</Directory>
In nginx, the equivalent is obtained via the directive:
location /path {
add_header TDM-a 0;
}