What does 第四台 mean in the context of immovable property? What does 第四台 mean, in the context of an immovable property site which e.g. rents out or sells rooms and buildings.
This is a Taiwanese term.

There were only three wireless TV stations in Taiwan long ago.

台視, 中視, 華視 (with the 教育頻道)

All other channels went to cable.

So, 第四台 means the cable TV.

If you see 老三台, it means the above original three stations.