<data> tag for tmx file

Question

What is stored in the data tag of of a tmx file such as the following

<data encoding="base64" compression="gzip">
 H4sIAAAAAAAAA+3YIQ6AMAwF0AEKEATwSO5/RCoRmGHY2BMvaVLzRb/pkVI6gOZ0oQ9DAVlynbd5DFOYH3Y1WcMW9gKytGbJ8HXWFtXaaQAAAAAA/s8Pm1xuBvLpDW9ciGmfRhAnAAA=
</data>

Also if this is key info, how is it read or extracted using c ?

Answer 1

This looks like binary octet data that has been compressed using gzip and then encoded in Base64 to make it XML-safe. Implementations for both should be easy to obtain, though I don't know enough C libraries to recommend one.