diff --git a/README.md b/README.md
index 7cd3a86..e04a52a 100644
--- a/README.md
+++ b/README.md
@@ -19,3 +19,20 @@ Use it like
 ```scala
 ClassPathUtil.classPath("/foo/${thing}/*:/a/b.jar") // Seq[java.nio.file.Path]
 ```
+
+## Details
+
+### Separator
+
+Just like the format that `java -cp` accepts, paths are split
+by an OS-dependent separator: `;` on Windows, `:` on Linux / macOS
+(and other Unix systems). *class-path-util* uses the separator
+returned by `java.io.File.pathSeparator`.
+
+### Globs
+
+`*` and `*.jar` are accepted at the end of a path. Case doesn't matter
+(`*.JAR` works too, for example). Both `*` and `*.jar` are equivalent,
+and make class-path-util add all the JARs (files ending in `.jar`,
+comparison done in a case-insensitive way) of the underlying directory
+to the class path.