diff --git a/lib/earmark_parser.ex b/lib/earmark_parser.ex
index 49ef870..6936e41 100644
--- a/lib/earmark_parser.ex
+++ b/lib/earmark_parser.ex
@@ -1,15 +1,15 @@
 defmodule EarmarkParser do
   @type ast_meta :: map()
-  @type ast_tag :: binary()
-  @type ast_attribute_name :: binary()
-  @type ast_attribute_value :: binary()
+  @type ast_tag :: String.t()
+  @type ast_attribute_name :: String.t()
+  @type ast_attribute_value :: String.t()
   @type ast_attribute :: {ast_attribute_name(), ast_attribute_value()}
   @type ast_attributes :: list(ast_attribute())
   @type ast_tuple :: {ast_tag(), ast_attributes(), ast(), ast_meta()}
-  @type ast_node :: binary() | ast_tuple()
+  @type ast_node :: String.t() | ast_tuple()
   @type ast :: list(ast_node())
 
-  @type error :: {atom(), non_neg_integer(), binary()}
+  @type error :: {atom(), non_neg_integer(), String.t()}
   @type errors :: list(error())
 
   @type t :: {:ok, ast(), []} | {:error, ast(), errors()}
@@ -615,7 +615,7 @@ defmodule EarmarkParser do
 
   The AST is exposed in the spirit of [Floki's](https://hex.pm/packages/floki).
   """
-  @spec as_ast(binary() | list(binary()), any()) :: t()
+  @spec as_ast(String.t() | list(String.t()), any()) :: t()
   def as_ast(lines, options \\ %Options{})
 
   def as_ast(lines, %Options{} = options) do
diff --git a/lib/earmark_parser/ast_renderer.ex b/lib/earmark_parser/ast_renderer.ex
index d339ba2..0b4e9d6 100644
--- a/lib/earmark_parser/ast_renderer.ex
+++ b/lib/earmark_parser/ast_renderer.ex
@@ -12,6 +12,7 @@ defmodule EarmarkParser.AstRenderer do
 
   @moduledoc false
 
+  @spec render([Block.t()], Context.t(), boolean()) :: Context.t()
   def render(blocks, context = %Context{options: %Options{}}, loose? \\ true) do
     _render(blocks, context, loose?)
   end
diff --git a/lib/earmark_parser/context.ex b/lib/earmark_parser/context.ex
index ec139ac..83c75ef 100644
--- a/lib/earmark_parser/context.ex
+++ b/lib/earmark_parser/context.ex
@@ -3,14 +3,14 @@ defmodule EarmarkParser.Context do
   alias EarmarkParser.Options
 
   @type t :: %__MODULE__{
-          options: EarmarkParser.Options.t(),
+          options: Options.t(),
           links: map(),
           footnotes: map(),
           referenced_footnote_ids: MapSet.t(String.t()),
           value: String.t() | [String.t()]
         }
 
-  defstruct options: %EarmarkParser.Options{},
+  defstruct options: %Options{},
             links: Map.new(),
             rules: nil,
             footnotes: Map.new(),
@@ -23,8 +23,8 @@ defmodule EarmarkParser.Context do
 
   @doc false
   def modify_value(%__MODULE__{value: value} = context, fun) do
-    nv = fun.(value)
-    %{context | value: nv}
+    new_value = fun.(value)
+    %{context | value: new_value}
   end
 
   @doc false
diff --git a/lib/earmark_parser/helpers/lookahead_helpers.ex b/lib/earmark_parser/helpers/lookahead_helpers.ex
index 7b66c0c..d610435 100644
--- a/lib/earmark_parser/helpers/lookahead_helpers.ex
+++ b/lib/earmark_parser/helpers/lookahead_helpers.ex
@@ -3,6 +3,9 @@ defmodule EarmarkParser.Helpers.LookaheadHelpers do
 
   import EarmarkParser.Helpers.LeexHelpers
 
+  @type backtix_string :: String.t()
+  @type natural :: non_neg_integer()
+
   @doc """
   Indicates if the _numbered_line_ passed in leaves an inline code block open.
 
@@ -11,6 +14,7 @@ defmodule EarmarkParser.Helpers.LookaheadHelpers do
 
   Otherwise `{nil, 0}` is returned
   """
+  @spec opens_inline_code(EarmarkParser.Line.t()) :: {backtix_string | nil, natural}
   def opens_inline_code(%{line: line, lnb: lnb}) do
     case tokenize(line, with: :earmark_parser_string_lexer) |> has_still_opening_backtix(nil) do
       nil -> {nil, 0}
@@ -26,6 +30,7 @@ defmodule EarmarkParser.Helpers.LookaheadHelpers do
   opening backtix
   """
   # (#{},{_,_}) -> {_,_}
+  @spec still_inline_code(EarmarkParser.Line.t(), {backtix_string, natural}) :: {backtix_string | nil, natural}
   def still_inline_code(%{line: line, lnb: lnb}, old = {pending, _pending_lnb}) do
     case tokenize(line, with: :earmark_parser_string_lexer) |> has_still_opening_backtix({:old, pending}) do
       nil -> {nil, 0}
diff --git a/lib/earmark_parser/line.ex b/lib/earmark_parser/line.ex
index cecc888..afd347c 100644
--- a/lib/earmark_parser/line.ex
+++ b/lib/earmark_parser/line.ex
@@ -94,6 +94,21 @@ defmodule EarmarkParser.Line do
       initial_indent: 0,
       list_indent: 0
     )
+
+    @type natural :: non_neg_integer()
+
+    @type t :: %__MODULE__{
+            annotation: nil | String.t(),
+            ial: nil | String.t(),
+            lnb: natural,
+            type: :ul | :ol,
+            line: String.t(),
+            indent: natural,
+            bullet: String.t(),
+            content: String.t(),
+            initial_indent: natural,
+            list_indent: natural
+          }
   end
 
   defmodule SetextUnderlineHeading do
diff --git a/lib/earmark_parser/line_scanner/rgx.ex b/lib/earmark_parser/line_scanner/rgx.ex
index dfc8185..b201162 100644
--- a/lib/earmark_parser/line_scanner/rgx.ex
+++ b/lib/earmark_parser/line_scanner/rgx.ex
@@ -159,7 +159,7 @@ defmodule EarmarkParser.LineScanner.Rgx do
     Regex.run(~r/\A (?:_\s?){3,} \z/x, content)
   end
 
-  @void_tags ~w{area br hr img wbr}
+  @void_tags ~w{area base br col embed hr img input link meta param source track wbr}
   def void_tag_rgx do
     ~r'''
     ^<( #{Enum.join(@void_tags, "|")} )
diff --git a/lib/earmark_parser/message.ex b/lib/earmark_parser/message.ex
index 97ef10e..8aba6f6 100644
--- a/lib/earmark_parser/message.ex
+++ b/lib/earmark_parser/message.ex
@@ -4,15 +4,17 @@ defmodule EarmarkParser.Message do
   alias EarmarkParser.Context
   alias EarmarkParser.Options
 
-  @type message_type :: :error | :warning
-  @type t :: {message_type, number, binary}
-  @type ts :: list(t)
-  @type container_type :: Options.t() | Context.t()
+  @type message_type :: :error | :warning | :deprecated
+  @type t :: {message_type, non_neg_integer(), String.t()}
+  @type ts :: [t()]
+  @type container :: Options.t() | Context.t()
 
+  @spec add_messages(container, ts()) :: container
   def add_messages(container, messages) do
     Enum.reduce(messages, container, &add_message(&2, &1))
   end
 
+  @spec add_message(container, t()) :: container
   def add_message(container, message)
 
   def add_message(options = %Options{}, message) do
@@ -23,6 +25,7 @@ defmodule EarmarkParser.Message do
     %{context | options: add_message(context.options, message)}
   end
 
+  @spec get_messages(container) :: ts()
   def get_messages(container)
 
   def get_messages(%Context{options: %{messages: messages}}) do
@@ -32,6 +35,7 @@ defmodule EarmarkParser.Message do
   @doc """
   For final output
   """
+  @spec sort_messages(container) :: [t()]
   def sort_messages(container) do
     container
     |> get_messages()
diff --git a/lib/earmark_parser/options.ex b/lib/earmark_parser/options.ex
index d447efe..8242c7d 100644
--- a/lib/earmark_parser/options.ex
+++ b/lib/earmark_parser/options.ex
@@ -32,6 +32,7 @@ defmodule EarmarkParser.Options do
             timeout: nil
 
   @type t :: %__MODULE__{
+          renderer: module(),
           all: boolean(),
           gfm: boolean(),
           gfm_tables: boolean(),
@@ -42,18 +43,19 @@ defmodule EarmarkParser.Options do
           parse_inline: boolean(),
 
           # allow for annotations
-          annotations: nil | binary(),
+          annotations: nil | String.t() | Regex.t(),
           # additional prefies for class of code blocks
-          code_class_prefix: nil | binary(),
+          code_class_prefix: nil | String.t(),
 
           # Filename and initial line number of the markdown block passed in
           # for meaningful error messages
-          file: binary(),
-          line: number(),
+          file: String.t(),
+          line: non_neg_integer(),
           # [{:error|:warning, lnb, text},...]
-          messages: MapSet.t(),
+          messages: MapSet.t(EarmarkParser.Message.t()),
           pure_links: boolean(),
           sub_sup: boolean(),
+          math: boolean(),
 
           # deprecated
           pedantic: boolean(),
@@ -105,22 +107,12 @@ defmodule EarmarkParser.Options do
         ...(1)> options.annotations
         ~r{\A(.*)(%%.*)}
   """
+  @spec normalize(t() | keyword()) :: t()
   def normalize(options)
 
   def normalize(%__MODULE__{} = options) do
-    case options.annotations do
-      %Regex{} ->
-        options
-
-      nil ->
-        options
-
-      _ ->
-        %{
-          options
-          | annotations: Regex.compile!("\\A(.*)(#{Regex.escape(options.annotations)}.*)")
-        }
-    end
+    options
+    |> _normalize_annotations()
     |> _set_all_if_applicable()
     |> _deprecate_old_messages()
   end
@@ -129,6 +121,18 @@ defmodule EarmarkParser.Options do
     struct(__MODULE__, options) |> normalize()
   end
 
+  defp _normalize_annotations(%__MODULE__{annotations: %Regex{}} = options) do
+    options
+  end
+
+  defp _normalize_annotations(%__MODULE__{annotations: nil} = options) do
+    options
+  end
+
+  defp _normalize_annotations(%__MODULE__{annotations: annotations} = options) do
+    %{options | annotations: Regex.compile!("\\A(.*)(#{Regex.escape(annotations)}.*)")}
+  end
+
   defp _deprecate_old_messages(options)
 
   defp _deprecate_old_messages(%__MODULE__{messages: %MapSet{}} = options) do
diff --git a/lib/earmark_parser/parser.ex b/lib/earmark_parser/parser.ex
index 9b1e874..0adfdd4 100644
--- a/lib/earmark_parser/parser.ex
+++ b/lib/earmark_parser/parser.ex
@@ -1,6 +1,6 @@
 defmodule EarmarkParser.Parser do
   @moduledoc false
-  alias EarmarkParser.{Block, Line, LineScanner, Options}
+  alias EarmarkParser.{Block, Line, LineScanner, Options, Context}
 
   import EarmarkParser.Helpers.{AttrParser, LineHelpers, ReparseHelpers}
 
@@ -19,6 +19,7 @@ defmodule EarmarkParser.Parser do
   The options are a `%EarmarkParser.Options{}` structure. See `as_html!`
   for more details.
   """
+  @spec parse_markdown([String.t()] | String.t(), Options.t()) :: {[Block.t()], Context.t()}
   def parse_markdown(lines, options)
 
   def parse_markdown(lines, options = %Options{}) when is_list(lines) do
@@ -513,7 +514,7 @@ defmodule EarmarkParser.Parser do
   # Consolidate multiline inline code blocks into an element #
   ############################################################
   @not_pending {nil, 0}
-  # ([#{},...]) -> {[#{}],[#{}],{'nil' | binary(),number()}}
+  # ([#{},...]) -> {[#{}],[#{}],{'nil' | String.t(),number()}}
   # @spec consolidate_para( ts ) :: { ts, ts, {nil | String.t, number} }
   defp consolidate_para(lines) do
     _consolidate_para(lines, [], @not_pending, nil)
diff --git a/lib/earmark_parser/parser/list_info.ex b/lib/earmark_parser/parser/list_info.ex
index 78435fb..bb39cad 100644
--- a/lib/earmark_parser/parser/list_info.ex
+++ b/lib/earmark_parser/parser/list_info.ex
@@ -1,28 +1,40 @@
 defmodule EarmarkParser.Parser.ListInfo do
+  alias EarmarkParser.{Options, Line, Line.ListItem}
+
   import EarmarkParser.Helpers.LookaheadHelpers, only: [opens_inline_code: 1, still_inline_code: 2]
 
   @moduledoc false
 
   @not_pending {nil, 0}
 
-  defstruct(
-    indent: 0,
-    lines: [],
-    loose?: false,
-    pending: @not_pending,
-    options: %EarmarkParser.Options{},
-    width: 0
-  )
-
-  def new(%EarmarkParser.Line.ListItem{initial_indent: ii, list_indent: width} = item, options) do
+  defstruct indent: 0,
+            lines: [],
+            loose?: false,
+            pending: @not_pending,
+            options: %Options{},
+            width: 0
+
+  @type t :: %__MODULE__{
+          indent: non_neg_integer(),
+          lines: [String.t()],
+          loose?: boolean(),
+          pending: {nil | String.t(), non_neg_integer()},
+          options: Options.t(),
+          width: non_neg_integer()
+        }
+
+  @spec new(ListItem.t(), Options.t()) :: t()
+  def new(%ListItem{initial_indent: ii, list_indent: width} = item, options) do
     pending = opens_inline_code(item)
     %__MODULE__{indent: ii, lines: [item.content], options: options, pending: pending, width: width}
   end
 
+  @spec update_list_info(t(), String.t(), Line.t(), boolean()) :: t()
   def update_list_info(list_info, line, pending_line, loose? \\ false) do
     prepend_line(list_info, line) |> _update_rest(pending_line, loose?)
   end
 
+  @spec prepend_line(t(), String.t()) :: t()
   def prepend_line(%__MODULE__{lines: lines} = list_info, line) do
     %{list_info | lines: [line | lines]}
   end
diff --git a/lib/earmark_parser/parser/list_parser.ex b/lib/earmark_parser/parser/list_parser.ex
index cbe356f..88d8d3e 100644
--- a/lib/earmark_parser/parser/list_parser.ex
+++ b/lib/earmark_parser/parser/list_parser.ex
@@ -10,6 +10,7 @@ defmodule EarmarkParser.Parser.ListParser do
 
   @not_pending {nil, 0}
 
+  @spec parse_list([Line.t()], [Block.t()], Options.t()) :: {[Block.t()], [Line.t()], Options.t()}
   def parse_list(lines, result, options \\ %Options{}) do
     {items, rest, options1} = _parse_list_items_init(lines, [], options)
     list = _make_list(items, _empty_list(items))