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.
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?