其背后的想法是，我们喜欢一段音乐是因为它的属性——为什么不利用音乐片段之间的相似性做一个音乐推荐系统呢？
The idea behind it is that we like music because of its attributes - and so why not design a music recommendation system that leverages the similarities between pieces of music.
版本4将属性分为三类：强制的、推荐的和命名的。
Version 4 classifies attributes into three categories: mandatory, recommended, and named.
推荐的属性描述了不同的文件系统类型和操作系统，考虑到了操作系统之间更好的包含和互操作性。
Recommended attributes represent different file system types and operating systems, and allow for better inclusion of, and interoperability between, operating systems.
应用推荐