I've been watching Star Trek: The Next Generation, and just recently transitioned into season two. Among several more significant changes, I've noticed that Worf's baldric has changed.
Season 1
Season 2
Here, the difference is quite apparent. The material and construction of the baldric is entirely different, as well as the emblems. A search for more images turns up at least one or two more variants - perhaps there are more. Most of the other variants are more subtle though and usually involve just changing the emblems on the baldric.
The baldric is a common piece of Klingon attire, and presumably Worf wears it to honor his heritage. Therefore, I think it is also a fair presumption that any changes he makes regarding his baldric would reflect something of significance of Klingon culture.
Has there ever been an in-universe explanation for these changes, or the significance of the differing emblems and styles of the Klingon baldrics?