Suppose a law is named something like “The Royal Decree of June 14, 2018 regulating the Distribution of Pharmaceuticals and Vitamins”. If a document needs to refer to that law more than once, it makes a mess and causes some painful reading. How should something like that with a date be abbreviated?
In the US we use the Bluebook standard, which gives various standard abbreviations for repeated uses. Is there some number the decree has that you could use instead of the full name? If you can’t find a standard abbreviation, you can kind of just make up your own reasonable abbreviation and describe it the first time you do it, e.g., “The Royal Decree of June 14, 2018 regulating the Distribution of Pharmaceuticals and Vitamins, [hereinafter Royal Decree of June 14, 2018].”