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Unix Time
Number of seconds that have elapsed since midnight Coordinated Universal Time (UTC), 1 January 1970, not counting leap seconds.
Language Code
Language codes are always a 2-character long lower-case string (e.g. en, de, ar). For more information, see:
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HTML String
Formatted content is represented as HTML. When dealing with such content, special characters must be escaped. Most programming languages provide utilities for this, such as Python with the cgi.escape function.