julia> module M
           struct T 
               "a field with a docstring"
               my_field
           end
           const C = T
           f() = T
       end
WARNING: replacing module M.
Main.M

help?> M.T.field
  Main.M.T has fields my_field.

help?> M.C.field
  Main.M.T has fields my_field.

help?> M.f().field
ERROR: MethodError: no method matching Base.Docs.Binding(::Type{Main.M.T}, ::Symbol)

Closest candidates are:
  Base.Docs.Binding(::Module, ::Symbol)
   @ Base docs/bindings.jl:9

Stacktrace:
 [1] top-level scope
   @ none:1

help?> M.T(1).field
ERROR: MethodError: no method matching Base.Docs.Binding(::Main.M.T, ::Symbol)

Closest candidates are:
  Base.Docs.Binding(::Module, ::Symbol)
   @ Base docs/bindings.jl:9

Stacktrace:
 [1] top-level scope
   @ none:1

help?> M.T(1).my_field
ERROR: MethodError: no method matching Base.Docs.Binding(::Main.M.T, ::Symbol)

Closest candidates are:
  Base.Docs.Binding(::Module, ::Symbol)
   @ Base docs/bindings.jl:9

Stacktrace:
 [1] top-level scope
   @ none:1

julia> x = M.T(1)
Main.M.T(1)

help?> x.field
ERROR: MethodError: no method matching Base.Docs.Binding(::Main.M.T, ::Symbol)

Closest candidates are:
  Base.Docs.Binding(::Module, ::Symbol)
   @ Base docs/bindings.jl:9

Stacktrace:
 [1] top-level scope
   @ ~/.julia/juliaup/julia-1.10.0-beta2+0.aarch64.apple.darwin14/share/julia/stdlib/v1.10/REPL/src/docview.jl:558