Manual:$wgUseESI

From Linux Web Expert

<translate> HTTP proxy (CDN) settings</translate>: $wgUseESI
If you run Squid3 with ESI support, enable this.
<translate> Introduced in version:</translate>1.2.0
<translate> Deprecated in version:</translate>1.33.0 (Gerrit change 468607; git #d63684a0)
<translate> Removed in version:</translate><translate> still in use</translate>
<translate> Allowed values:</translate>(boolean)
<translate> Default value:</translate>false

Details

If you run Squid3 with ESI support, enable this.