diff --git a/htdocs/langs/en_US/errors.lang b/htdocs/langs/en_US/errors.lang
index d2236dee4e0..2560f248a9b 100644
--- a/htdocs/langs/en_US/errors.lang
+++ b/htdocs/langs/en_US/errors.lang
@@ -76,7 +76,7 @@ ErrorNoValueForCheckBoxType=Please fill value for checkbox list
 ErrorNoValueForRadioType=Please fill value for radio list
 ErrorBadFormatValueList=The list value cannot have more than one comma: <u>%s</u>, but need at least one: key,value
 ErrorFieldCanNotContainSpecialCharacters=The field <b>%s</b> must not contains special characters.
-ErrorFieldCanNotContainSpecialNorUpperCharacters=The field <b>%s</b> must not contain special characters, nor upper case characters and cannot contain only numbers.
+ErrorFieldCanNotContainSpecialNorUpperCharacters=The field <b>%s</b> must not contain special characters, nor upper case characters, and must start with an alphabetical character (a-z)
 ErrorFieldMustHaveXChar=The field <b>%s</b> must have at least %s characters.
 ErrorNoAccountancyModuleLoaded=No accountancy module activated
 ErrorExportDuplicateProfil=This profile name already exists for this export set.