I rarely see any on the 4 variations talked about in the initial write-up. All four of such variants are proper. A single could argue that they're much more proper than "Sincerely yours". Any of these would be a refreshing transform from studying yet another American variety letter. 知乎，让每一次点击都充满意义 —— https://simonucqjf.shotblogs.com/considerations-to-know-about-legal-advisor-in-dha-karachi-pakistan-52170433