I've noticed that ea.com includes a <meta name="lc" content="en_us"/> tag on their website which changes for each language/country (<meta name="lc" content="en_gb"/>, <meta name="lc" content="es_mx"/>, &c).
I can't find any reference to name="lc" being a valid meta tag. I've seen <meta http-equiv="content-language" content="en"> and <html lang="en">, but where did name="lc" come from?
As Stephen said, it is mostly likely an attempt at defining locale. In some of the web-based software that I've worked with, I've come across form values and URLs like:
<input type="hidden" name="lc" value="US">
Or
page.php?id=233&lc=FRA
The meta tag for "lc" is undocumented, which means that it is either a mistake or some sort of custom tag that is used for internal purposes.
It is not valid.
ea.com is using HTML5, but in HTML5 it is only allowed to use name values that are
lc is not included.
If they were using older HTML versions (e.g., HTML 4.01), it would be valid to use this value.
<meta property="og:locale" content="en_GB" />which is as close as I could find to something valid and documented.