diff --git a/data/memoffset.toml b/data/memoffset.toml
new file mode 100644
index 0000000..864cf2c
--- /dev/null
+++ b/data/memoffset.toml
@@ -0,0 +1,7 @@
+description = """
+Most of the functionality of this crate now exists in `std::mem::offset_of!` as \
+of Rust 1.77.
+
+The functionality of `span_of!` does not exist in the standard library.
+"""
+url = "https://doc.rust-lang.org/std/mem/macro.offset_of.html"