wp_crm_system_display_links filter controls whether or not there will be links on the Contacts or Organizations table (WP-CRM System > Contacts/Organizations).
By default the phone numbers and email addresses will be linked so that you can easily email or call the numbers when viewing the data on a mobile phone. One tap, and the phone number will be dialed, or an email addressed to the email address will pop up.
This isn't always desired, so the filter will control whether or not the links are displayed.
This filter expects either true or false to be returned. By default, it will return true.
To change this, use the following code in your theme's functions.php file or in a custom plugin.
add_filter( 'wp_crm_system_display_links', '__return_false' );