diff --git a/docs/src/mainapi.md b/docs/src/mainapi.md
index f3bb370..1ea66cf 100644
--- a/docs/src/mainapi.md
+++ b/docs/src/mainapi.md
@@ -23,9 +23,10 @@ DiffEqBase.ODEProblem(::FSPSystem, u0, tmax, p)
 
 ## Steady-State Problems
 
-Computing steady-state distributions can be done using the SteadyStateDiffEq.jl package. At the moment FiniteStateProjection.jl adjusts the rate matrix so that reactions leaving the truncated state space have propensity 0.
+Computing steady-state distributions can be done using the SteadyStateDiffEq.jl package. At the moment FiniteStateProjection.jl adjusts the rate matrix so that reactions leaving the truncated state space have propensity 0. Pass a [`SteadyState`](@ref) instance to the conversion methods to request this steady-state formulation.
 
 ```@docs
+SteadyState
 Base.convert(::Type{ODEFunction}, ::FSPSystem, ::SteadyState)
 DiffEqBase.SteadyStateProblem(::FSPSystem, u0, p)
 ```
diff --git a/src/build_rhs_ss.jl b/src/build_rhs_ss.jl
index d6f662d..81fb7ad 100644
--- a/src/build_rhs_ss.jl
+++ b/src/build_rhs_ss.jl
@@ -1,3 +1,18 @@
+"""
+    struct SteadyState end
+
+Marker type used to select the steady-state formulation of the Chemical
+Master Equation. Passing a `SteadyState()` instance to the conversion and
+matrix-building methods requests the right-hand side in which transitions
+out of the truncated state space are dropped (their propensity is set to
+zero), as required for solving for the stationary distribution rather than
+the time-dependent one.
+
+It is used as a dispatch tag by
+[`Base.convert(::Type{ODEFunction}, ::FSPSystem, ::SteadyState)`](@ref),
+[`SparseArrays.SparseMatrixCSC(::FSPSystem, ::NTuple, ps, ::SteadyState)`](@ref)
+and [`DiffEqBase.SteadyStateProblem(::FSPSystem, u0, p)`](@ref).
+"""
 struct SteadyState end
 
 """