Reason: halter and halter_top are synonymous and both in relatively frequent usage. I don't really have a preference for one way over the other, but they should probably be merged. Popular usage indicates halter is more commonly used.
As per the wiki article, what's being described is the manner in which a garment goes around the neck. It seems inappropriate to define the tag as a specific type of shirt. While there are only a handful of halter dresses, there's a bunch more halter swimsuits that utilize the style.
