Table 9-22 shows the template patterns available for formatting date and time values.
Attempting to enter a date using a mixture of ISO 8601 week-numbering fields and Gregorian date fields is nonsensical, and will cause an error.
USCIS often requires that copies of vital statistics records and civil documents from foreign countries be submitted with most applications, including naturalization applications.
$langcode: (optional) Language code to translate to. The 6.x function takes small, medium and large, as aiquandol points out.
Maybe the 6 and 7 documentation should be separated?
In the context of an ISO 8601 week-numbering year, the concept of a If you see anything in the documentation that is not correct, does not match your experience with the particular feature or requires further clarification, please use this form to report a documentation issue.
$format: (optional) If $type is 'custom', a PHP date format string suitable for input to date().
Any text that is not a template pattern is simply copied verbatim.