diff --git a/nalgebra-sparse/Cargo.toml b/nalgebra-sparse/Cargo.toml
index b85fea2c..7692984e 100644
--- a/nalgebra-sparse/Cargo.toml
+++ b/nalgebra-sparse/Cargo.toml
@@ -15,6 +15,8 @@ license = "Apache-2.0"
 [features]
 proptest-support = ["proptest", "nalgebra/proptest-support"]
 compare = [ "matrixcompare-core" ]
+
+# Enable matrix market I/O
 io      = [ "pest", "pest_derive" ]
 
 # Enable to enable running some tests that take a lot of time to run
diff --git a/nalgebra-sparse/src/lib.rs b/nalgebra-sparse/src/lib.rs
index a588787f..edbf83bd 100644
--- a/nalgebra-sparse/src/lib.rs
+++ b/nalgebra-sparse/src/lib.rs
@@ -19,6 +19,7 @@
 //! - Sparsity patterns in CSR and CSC matrices are explicitly represented by the
 //!   [SparsityPattern](pattern::SparsityPattern) type, which encodes the invariants of the
 //!   associated index data structures.
+//! - [Matrix market format support](`io`) when the `io` feature is enabled.
 //! - [proptest strategies](`proptest`) for sparse matrices when the feature
 //!   `proptest-support` is enabled.
 //! - [matrixcompare support](https://crates.io/crates/matrixcompare) for effortless