diff --git a/ext_conf_template.txt b/ext_conf_template.txt
index 67de249d..6f723f25 100755
--- a/ext_conf_template.txt
+++ b/ext_conf_template.txt
@@ -5,4 +5,10 @@ backwardsCompatFormat = %1$s %3$s
 storeBackwardsCompatName = 1
 
   # cat=basic; type=boolean; label=Name field is read only
-readOnlyNameField = 1
\ No newline at end of file
+readOnlyNameField = 1
+
+  # cat=backend; type=text; label=Pattern for validation telephone number in TCA with PHP
+telephoneValidationPatternForPhp = /[^\d\+\s\-]/
+
+  # cat=backend; type=text; label=Pattern for validation telephone number in TCA with JS
+telephoneValidationPatternForJs = /[^\d\+\s\-]/g