I dug into how the season format was formed in both Urusei Yatsura and Inuyasha. In the case of Inuyasha, it appears to be due to a DVD set. In the case of Urusei Yatsura, it appears to be due to changes in chief screenwriters and series directors, but as I checked in Japanese and the credits in openings and endings, there's a chance that the information in wikipedia might be mistaken. Until I get to the bottom of this, let's not indicate about seasons.
Unlike Kyoukai no Rinne, Urusei Yatsura is not well known to be split in seasons especially since the episodes are all uploaded in one format, but if the season format is correct, I'll just add SEASON FORMAT in the episode infobox