How to properly use the language files in joomla

问题:

As far as i could dig in thought google, i found something like:

<languages>
<language tag="en-GB">en-GB.whatever.ini</language>
<language tag="en-GB">en-GB.whatever.sys.ini</language>
</languages>

From here some question:

1. Can i use it without tag and somehow specify to use with the default system language
2. What is the difference between whatever.ini and whatever.sys.ini
3. Do I have something else to write to xml or those 4 lines uploads and runs languages

回答1:

1. The tag="en-GB" is required.
2. .ini contains ALL the translations including the description for an extension when it it opened up in the Module or plugin Manager....sys.ini is used to define the description of the extension upon installation.
3. The code you provided in the XML is fine ;)