diff --git a/base/show.jl b/base/show.jl
index 879916d794f96..14373604fe6f5 100644
--- a/base/show.jl
+++ b/base/show.jl
@@ -3222,17 +3222,23 @@ end
 summary(io::IO, f::Function) = show(io, MIME"text/plain"(), f)
 
 """
-    showarg(io::IO, x, toplevel)
+    Base.showarg(io::IO, x, toplevel)
 
-Show `x` as if it were an argument to a function. This function is
-used by [`summary`](@ref) to display type information in terms of sequences of
-function calls on objects. `toplevel` is `true` if this is
-the direct call from `summary` and `false` for nested (recursive) calls.
+Show the quasi-type of `x` where quasi-type is the type of `x` or an expression (possibly
+containing quasi-types) that would generate an object of the same type as `x`. The shorter
+of these two options is typically used.
 
-The fallback definition is to print `x` as "::\\\$(typeof(x))",
-representing argument `x` in terms of its type. (The double-colon is
-omitted if `toplevel=true`.) However, you can
-specialize this function for specific types to customize printing.
+This function is used by summary to display type information in terms of sequences of
+function calls on objects.
+
+Show a leading `::` if `toplevel` is `false` and showing a type. `toplevel` is `true` if
+this is the direct call from `summary` and `false` for nested (recursive) calls.
+
+The fallback definition is to print x as "::$(typeof(x))", representing argument x in terms
+of its type. (The double-colon is omitted if toplevel=true.) However, you can specialize
+this function for specific types to customize printing. This customization is useful for
+types that have simple constructors and verbose types such as `reinterpret`ed arrays or
+`SubArray`s.
 
 # Examples
 
@@ -3261,14 +3267,14 @@ type, indicating that any recursed calls are not at the top level.
 Printing the parent as `::Array{Float64,3}` is the fallback (non-toplevel)
 behavior, because no specialized method for `Array` has been defined.
 """
-function showarg(io::IO, T::Type, toplevel)
-    toplevel || print(io, "::")
-    print(io, "Type{", T, "}")
-end
 function showarg(io::IO, @nospecialize(x), toplevel)
     toplevel || print(io, "::")
     print(io, typeof(x))
 end
+function showarg(io::IO, T::Type, toplevel)
+    toplevel || print(io, "::")
+    print(io, "Type{", T, "}")
+end
 # This method resolves an ambiguity for packages that specialize on eltype
 function showarg(io::IO, a::Array{Union{}}, toplevel)
     toplevel || print(io, "::")