diff --git a/resources/phonenumber.proto b/resources/phonenumber.proto
index 10683430b..12c906203 100644
--- a/resources/phonenumber.proto
+++ b/resources/phonenumber.proto
@@ -26,16 +26,17 @@ package i18n.phonenumbers;
 
 message PhoneNumber {
 // The country calling code for this number, as defined by the International Telecommunication Union
-// (ITU). Fox example, this would be 1 for NANPA countries, and 33 for France.
+// (ITU). For example, this would be 1 for NANPA countries, and 33 for France.
   required int32 country_code = 1;
 
 // National (significant) Number is defined in International Telecommunication Union (ITU)
 // Recommendation E.164. It is a language/country-neutral representation of a phone number at a
-// country level. For countries which have the concept of Area Code, the National (significant)
-// Number contains the area code. It contains a maximum number of digits which equal to 15 - n,
-// where n is the number of digits of the country code. Take note that National (significant) Number
-// does not contain National(trunk) prefix. Obviously, as a uint64, it will never contain any
-// formatting (hypens, spaces, parentheses), nor any alphanumeric spellings.
+// country level. For countries which have the concept of an "area code" or "national destination
+// code", this is included in the National (significant) Number. Although the ITU says the maximum
+// length should be 15, we have found longer numbers in some countries e.g. Germany.
+// Note that the National (significant) Number does not contain the National(trunk) prefix.
+// Obviously, as a uint64, it will never contain any formatting (hyphens, spaces, parentheses), nor
+// any alphanumeric spellings.
   required uint64 national_number = 2;
 
 // Extension is not standardized in ITU recommendations, except for being defined as a series of