Did not find better (shorter) way until today.
In /home/odoo-test/odoo-test/addons/pos_lapagept/__openerp__.py :
{
'depends' : ['point_of_sale',],
"data" : [
'lapagept_templates.xml',
],
}
In /home/odoo-test/odoo-test/addons/pos_lapagept/lapagept_templates.xml :
<?xml version="1.0" encoding="utf-8"?>
<openerp>
<data>
<template id="index_as" name="POS Index - AS"><!DOCTYPE html>
<html>
<head>
<title>Odoo POS - AS</title>
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
<meta http-equiv="content-type" content="text/html, charset=utf-8" />
<meta name="viewport" content=" width=1024, user-scalable=no"/>
<meta name="apple-mobile-web-app-capable" content="yes"/>
<meta name="mobile-web-app-capable" content="yes"/>
<link rel="shortcut icon" sizes="196x196" href="/point_of_sale/static/src/img/touch-icon-196.png"/>
<link rel="shortcut icon" sizes="128x128" href="/point_of_sale/static/src/img/touch-icon-128.png"/>
<link rel="apple-touch-icon" href="/point_of_sale/static/src/img/touch-icon-iphone.png"/>
<link rel="apple-touch-icon" sizes="76x76" href="/point_of_sale/static/src/img/touch-icon-ipad.png"/>
<link rel="apple-touch-icon" sizes="120x120" href="/point_of_sale/static/src/img/touch-icon-iphone-retina.png"/>
<link rel="apple-touch-icon" sizes="152x152" href="/point_of_sale/static/src/img/touch-icon-ipad-retina.png"/>
<link rel="shortcut icon" href="/web/static/src/img/favicon.ico" type="image/x-icon"/>
<link rel="stylesheet" href="/point_of_sale/static/src/fonts/lato/stylesheet.css" />
<link rel="stylesheet" href="/point_of_sale/static/src/fonts/font-awesome-4.0.3/css/font-awesome.min.css" />
<link rel="stylesheet" href="/point_of_sale/static/src/css/pos.css" id="pos-stylesheet"/>
<link rel="stylesheet" href="/pos_lapagept/static/src/css/pos_as.css"/>
<link rel="stylesheet" href="/point_of_sale/static/src/css/keyboard.css" />
<t t-call-assets="web.assets_common" t-css="false" />
<t t-call-assets="web.assets_backend" t-css="false" />
<script type="text/javascript" id="loading-script">
$(function() {
var s = new openerp.init(<t t-raw='modules' />);
<t t-raw='init' />
});
</script>
</head>
<body>
<div class='openerp openerp_webclient_container'>
<table class='oe_webclient'>
<tr>
<td class='oe_application' />
</tr>
</table>
</div>
</body>
</html>
</template>
<template id="index_pt" name="POS Index - PT"><!DOCTYPE html>
<html>
<head>
<title>Odoo POS - PT</title>
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
<meta http-equiv="content-type" content="text/html, charset=utf-8" />
<meta name="viewport" content=" width=1024, user-scalable=no"/>
<meta name="apple-mobile-web-app-capable" content="yes"/>
<meta name="mobile-web-app-capable" content="yes"/>
<link rel="shortcut icon" sizes="196x196" href="/point_of_sale/static/src/img/touch-icon-196.png"/>
<link rel="shortcut icon" sizes="128x128" href="/point_of_sale/static/src/img/touch-icon-128.png"/>
<link rel="apple-touch-icon" href="/point_of_sale/static/src/img/touch-icon-iphone.png"/>
<link rel="apple-touch-icon" sizes="76x76" href="/point_of_sale/static/src/img/touch-icon-ipad.png"/>
<link rel="apple-touch-icon" sizes="120x120" href="/point_of_sale/static/src/img/touch-icon-iphone-retina.png"/>
<link rel="apple-touch-icon" sizes="152x152" href="/point_of_sale/static/src/img/touch-icon-ipad-retina.png"/>
<link rel="shortcut icon" href="/web/static/src/img/favicon.ico" type="image/x-icon"/>
<link rel="stylesheet" href="/point_of_sale/static/src/fonts/lato/stylesheet.css" />
<link rel="stylesheet" href="/point_of_sale/static/src/fonts/font-awesome-4.0.3/css/font-awesome.min.css" />
<link rel="stylesheet" href="/point_of_sale/static/src/css/pos.css" id="pos-stylesheet"/>
<link rel="stylesheet" href="/pos_lapagept/static/src/css/pos_pt.css"/>
<link rel="stylesheet" href="/point_of_sale/static/src/css/keyboard.css" />
<t t-call-assets="web.assets_common" t-css="false" />
<t t-call-assets="web.assets_backend" t-css="false" />
<script type="text/javascript" id="loading-script">
$(function() {
var s = new openerp.init(<t t-raw='modules' />);
<t t-raw='init' />
});
</script>
</head>
<body>
<div class='openerp openerp_webclient_container'>
<table class='oe_webclient'>
<tr>
<td class='oe_application' />
</tr>
</table>
</div>
</body>
</html>
</template>
</data>
</openerp>
All the CSS in the file /home/odoo-test/odoo-test/addons/pos_lapagept/static/src/css/pos_as.css will override the CSS in the original pos.css file. It works very well.
But now, somebody here could say to me why it's written « Odoo » rather than « Odoo POS - AS » when I inspect the code. See below image. ??????