Explain Unicode license agreement

Cargo.toml

@@ -4,7 +4,7 @@ version = "1.0.1"
 authors = ["David Tolnay <dtolnay@gmail.com>"]
 edition = "2018"
 rust-version = "1.31"
-license = "MIT OR Apache-2.0"
+license = "(MIT OR Apache-2.0) AND Unicode-DFS-2016"
 description = "Determine whether characters have the XID_Start or XID_Continue properties according to Unicode Standard Annex #31"
 repository = "https://github.com/dtolnay/unicode-ident"
 documentation = "https://docs.rs/unicode-ident"

LICENSE-UNICODE

@@ -0,0 +1,46 @@
+UNICODE, INC. LICENSE AGREEMENT - DATA FILES AND SOFTWARE
+
+See Terms of Use <https://www.unicode.org/copyright.html>
+for definitions of Unicode Inc.’s Data Files and Software.
+
+NOTICE TO USER: Carefully read the following legal agreement.
+BY DOWNLOADING, INSTALLING, COPYING OR OTHERWISE USING UNICODE INC.'S
+DATA FILES ("DATA FILES"), AND/OR SOFTWARE ("SOFTWARE"),
+YOU UNEQUIVOCALLY ACCEPT, AND AGREE TO BE BOUND BY, ALL OF THE
+TERMS AND CONDITIONS OF THIS AGREEMENT.
+IF YOU DO NOT AGREE, DO NOT DOWNLOAD, INSTALL, COPY, DISTRIBUTE OR USE
+THE DATA FILES OR SOFTWARE.
+
+COPYRIGHT AND PERMISSION NOTICE
+
+Copyright © 1991-2022 Unicode, Inc. All rights reserved.
+Distributed under the Terms of Use in https://www.unicode.org/copyright.html.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Unicode data files and any associated documentation
+(the "Data Files") or Unicode software and any associated documentation
+(the "Software") to deal in the Data Files or Software
+without restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, and/or sell copies of
+the Data Files or Software, and to permit persons to whom the Data Files
+or Software are furnished to do so, provided that either
+(a) this copyright and permission notice appear with all copies
+of the Data Files or Software, or
+(b) this copyright and permission notice appear in associated
+Documentation.
+
+THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS
+NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL
+DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THE DATA FILES OR SOFTWARE.
+
+Except as contained in this notice, the name of a copyright holder
+shall not be used in advertising or otherwise to promote the sale,
+use or other dealings in these Data Files or Software without prior
+written authorization of the copyright holder.

README.md

@@ -263,15 +263,21 @@ is_xid_start:
 
 ## License
 
-<sup>
-Licensed under either of <a href="LICENSE-APACHE">Apache License, Version
-2.0</a> or <a href="LICENSE-MIT">MIT license</a> at your option.
-</sup>
+Use of the Unicode Character Database, as this crate does, is governed by the <a
+href="LICENSE-UNICODE">Unicode License Agreement &ndash; Data Files and Software
+(2016)</a>.
 
-<br>
+All intellectual property within this crate that is **not generated** using the
+Unicode Character Database as input is licensed under either of <a
+href="LICENSE-APACHE">Apache License, Version 2.0</a> or <a
+href="LICENSE-MIT">MIT license</a> at your option.
+
+The **generated** files incorporate tabular data derived from the Unicode
+Character Database, together with intellectual property from the original source
+code content of the crate. One must comply with the terms of both the Unicode
+License Agreement and either of the Apache license or MIT license when those
+generated files are involved.
 
-<sub>
 Unless you explicitly state otherwise, any contribution intentionally submitted
 for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
-be dual licensed as above, without any additional terms or conditions.
-</sub>
+be licensed as just described, without any additional terms or conditions.