omission from earlier commit

Author: thchr

docs/src/operations.md

@@ -53,4 +53,7 @@ inv(op1) # inv(3₁₁₁⁺)
 
 ## Action of symmetry operators
 A `SymOperation` can act on vectors in direct ([`RVec`](@ref)) or reciprocal ([`KVec`](@ref)) space.
-When acting in reciprocal space, translation parts of a `SymOperation` have no effect.
+When acting in reciprocal space, translation parts of a `SymOperation` have no effect.
+
+# Magnetic symmetry operations
+Magnetic symmetry operations that may incorporate composition with an anti-unitary time-reversal operation can be created via [`MSymOperation`](@ref) (see also [`mspacegroup`](@ref)).