rwsimon

Looking at the taxonomies documentation page, as you suggested, I found this:

Taxonomies
Custom taxonomies could be found inside realia/includes/taxonomies folder. Before you start working with taxonomies, make sure that you are familiar with all nuances of register_taxonomy function.

List of all available custom taxonomies defined by plugin:

Locations
Property types
Statuses
Amenities
Materials

There is any kind of setting, in the taxonomies, linked to the filter RENT / SALE.

In the plugin main php file, I found this setting defined in constant:

public function constants() {
			define( 'REALIA_DIR', plugin_dir_path( __FILE__ ) );
			define( 'REALIA_PROPERTY_PREFIX', 'property_' );
			define( 'REALIA_AGENCY_PREFIX', 'agency_' );
			define( 'REALIA_AGENT_PREFIX', 'agent_' );
			define( 'REALIA_TRANSACTION_PREFIX', 'transaction_' );
			define( 'REALIA_PACKAGE_PREFIX', 'user_' );
			define( 'REALIA_USER_PREFIX', 'user_' );
			define( 'REALIA_RECAPTCHA_URL', 'https://www.google.com/recaptcha/api/siteverify' );
<strong>	        define( 'REALIA_CONTRACT_SALE', 'SALE' );
	        define( 'REALIA_CONTRACT_RENT', 'RENT' );</strong>

Removing or commenting this constant definition does get any effect. And your suggestion to remove this does not make any sense, since this item is not from a taxonomy.

If this setting was a real taxonomy, we can just remove it via wordpress admin.