The individual entries are summaries; where a specific entry has more information in the full document a link, denoted [*], is provided. The statuses Supported, Experimental, and so on, are likewise defined in the full document.
Sometimes the same feature, or a similar feature, is named differently in the documentation for different releases. In such cases the table will show it as two separate features, with a discontinuity in support, even though support may have been continuous.
The support status of versions earlier than listed here is documented on the wiki.