Try this if you are comfortable making code edits to the \includes\modules\shipping\usps.php file
NOT the language file as this thread is titled.
This is working for me, but I am not able to offer any support other than the edits that I made.
I have customized the max volume for first class packages to be 12.5 cubic inches for our particular business needs (highlighted in RED). If you are using a different value as your max volume for first class, you will also need to make that edit. The module default was 0, if I remember correctly.
Around line number 248, changes this
'First-Class Mail International Parcel**'=>
array('maxWeight'=>70, 'maxGL'=>'', 'volume'=>[B]12.5[/B], 'maxLength'=>'', 'maxWidth'=>'','maxHeight'=>'', 'name'=>'First Class Mail Int Parcel'), // ID="15"
to THIS
'First-Class [B]Package International Service[/B]**'=>
array('maxWeight'=>70, 'maxGL'=>'', 'volume'=>[B]12.5[/B], 'maxLength'=>'', 'maxWidth'=>'','maxHeight'=>'', 'name'=>'First Class Mail Int [B]Package[/B]'), // ID="15"
around line 276
Change this
'First Class Mail Int Parcel' => 'First-Class Mail International Parcel**',
to this
'First Class Mail Int Parcel' => 'First-Class [B]Package International Service[/B]**',
Many thanks to Ajeh for her help with the changes.
Rick
RixStix (dot) com
aka: ChainWeavers (dot) com