From Wikisubttiles

Problems until the new feature's existence

Before the "linked versions" feature, users usually download a subtitles file for a video version, adapt it to another video version, an then upload again to wikisubtitles as "a new version". This procedure has the problem that all the modifications in the texts, and all the translations are not transmitted from one version to another.

How the "linked versions" work

Now, there is a link in each version, next to "Start a new translation" link, which allows to upload an adapted subtitles file to another video version. When this SRT file is uploaded, only the times are read, not the labels, so it has not any sense to correct some labels before the file is uploaded. When the upload procedure is completed, a new "linked version" appears on the subtitle summary, with all the languages existing in the "original version". So, when someone downloads a linked versions, times are read from the linked version, but labels are read from the original versions, including the translations. It is mandatory that the adapted file has to have the same number of sequences than the original file. Otherwise, you'll get an error.

Example

A show episode appears like XOR version, the subtitles are made for this version and some translations are made on wikisubtitles, maybe they will be completed, maybe no. Someone download that file and adapt it to the version 720p, with Subtitles Workshop, for example, using the same number of sequences, without adding or deleting any sequence, just adapting the times to the new version. When the adaptation is completed, that person upload the new file to wikisubtitles as a "linked version", so wikisubtitles will only read the times from that SRT file. A new version is created, with all the translations of the original version, and all the modifications made on that original version, are transmitted to the linked version when someone download it!