diff --git a/README.md b/README.md
new file mode 100644
index 0000000..7af2e23
--- /dev/null
+++ b/README.md
@@ -0,0 +1,30 @@
+# refset - non-owning `HsahSet`
+
+A hash-set analogue that does not own its data.
+
+It can be used to "mark" items without the need to transfer ownership to the map
+
+# Example use case
+ ```rust
+ /// Process arguments while ignoring duplicates
+ fn process_args(args: impl IntoIterator<Item=String>) {
+   let mut same=  HashRefSet::new();
+   for argument in args.into_iter()
+   {
+     if !same.insert(argument.as_str()) {
+       // Already processed this input, ignore
+       continue;
+     }
+     //do work...
+   }
+ }
+ ```
+# Serialisation support with `serde` crate
+ `HashRefSet` and `HashType` both implement `Serialize` and `Deserialize` from the `serde` crate if the `serde` feature is enabled. By default it is not.
+ 
+# Drawbacks
+ Since the item is not inserted itself, we cannot use `Eq` to double check there was not a hash collision.
+ While the hashing algorithm used (Sha512) is extremely unlikely to produce collisions, especially for small data types, keep in mind that it is not infallible.
+
+# License
+MIT