From a Google Pagespeed Insights test it seems my MediaWiki website lacks text-compression;
reading about this, it seems I lack this because I don't have Gzip compression on.
I Ran this gzip test and it seems indeed my website lacks Gzip compression.
Interpreting this article, I tried to add Gzip by adding to following input to the end of LocalSettings.php:
$wgUseGzip = true;
Yet Gzip wasn't added.
I find no other manual literature about this
How to allow Gzip for a MediaWiki website?
You can activate compression using .htaccess file if your server supports it.
Just create a ".htaccess" file on your http root with this contents and run the test again:
<ifModule mod_gzip.c>
mod_gzip_on Yes
mod_gzip_dechunk Yes
mod_gzip_item_include file .(html?|txt|css|js|php|pl)$
mod_gzip_item_include handler ^cgi-script$
mod_gzip_item_include mime ^text/.*
mod_gzip_item_include mime ^application/x-javascript.*
mod_gzip_item_exclude mime ^image/.*
mod_gzip_item_exclude rspheader ^Content-Encoding:.*gzip.*
</ifModule>
$wgUseGzipis specific to using the file cache (as the documentation page tells yout).