While many things in the frontend can be configured using the frontend itself, some customisations are currently only possible by editing a definitions file.
This file is
defines.inc.php located in /include of the Zabbix HTML document directory.
Parameters in this file that could be of interest to users:
Minimum graph period, in seconds. One minute by default.
Default location of Y axis in simple graphs and default value for drop down box when adding items to custom graphs. Possible values: 0 - left, 1 - right.
Used in screens and defines the number of seconds after which query skipping will be switched off. Otherwise, if a screen element is in update status all queries on update are skipped until a response is received. With this parameter in use, another update query might be sent after N seconds without having to wait for the response to the first one.
String used as the name of the Zabbix frontend session cookie.
TTL timeout in seconds used to invalidate data cache of Vault response. Set 0 to disable Vault response caching.