1 files changed, 26 insertions, 0 deletions
diff --git a/bs4/element.py b/bs4/element.py
index 3eed924..57a24d0 100644
--- a/bs4/element.py
+++ b/bs4/element.py
@@ -1012,6 +1012,11 @@ class NavigableString(str, PageElement):
 
         # Do nothing if the caller is looking for specific types of
         # string, and we're of a different type.
+        #
+        # We check specific types instead of using isinstance(self,
+        # types) because all of these classes subclass
+        # NavigableString. Anyone who's using this feature probably
+        # wants generic NavigableStrings but not other stuff.
         my_type = type(self)
         if types is not None:
             if isinstance(types, type):
@@ -1140,6 +1145,27 @@ class TemplateString(NavigableString):
     pass
 
 
+class RubyTextString(NavigableString):
+    """A NavigableString representing the contents of the <rt> HTML
+    element.
+
+    https://dev.w3.org/html5/spec-LC/text-level-semantics.html#the-rt-element
+
+    Can be used to distinguish such strings from the strings they're
+    annotating.
+    """
+    pass
+
+
+class RubyParenthesisString(NavigableString):
+    """A NavigableString representing the contents of the <rp> HTML
+    element.
+
+    https://dev.w3.org/html5/spec-LC/text-level-semantics.html#the-rp-element
+    """
+    pass
+
+
 class Tag(PageElement):
     """Represents an HTML or XML tag that is part of a parse tree, along
     with its attributes and contents.