Clarification about language tag

Pardon me for the trivial question.

In Turtle syntax the @lang tag syntax refers to BCP47 that states:

language      = 2*3ALPHA            ; shortest ISO 639 code

That is, the language code (I ignore all the variants here) should be 2 
or 3 characters. Indeed ISO 639 
(http://www.loc.gov/standards/iso639-2/php/code_list.php) lists both 2 
and 3 chars codes (e.g., English: 'en' and 'eng').

But in all Turtle examples I have found the language code has 2 chars. 
Is it a requirement or is simply a tradition? This means, could I write 
"Pancake"@eng?

The question arises because WordNet contains 3 chars codes, so to 
transform into triples, should/shouldn't I convert it to 2 characters?

Thanks for your patience

    mario

-- 
Ing. Mario Valle
Swiss National Supercomputing Centre (CSCS)
v. Trevano 131, 6900 Lugano, Switzerland
Tel: +41 (91) 610.82.60

Received on Tuesday, 20 December 2016 16:17:09 UTC