From what I understand, 使用 is just a more formal (书面语) variant of 用。 In your example, the 是－－－的 pattern is for emphasis. In this case, it is emphasizing that there ARE regulations for the use of traditional characters. If you look up the 是－－－的 pattern, you can see the use of it in more colloquial speech as well.
Posted on: Simplified vs Traditional Characters
December 13, 2014 at 12:23 AMFrom what I understand, 使用 is just a more formal (书面语) variant of 用。 In your example, the 是－－－的 pattern is for emphasis. In this case, it is emphasizing that there ARE regulations for the use of traditional characters. If you look up the 是－－－的 pattern, you can see the use of it in more colloquial speech as well.