diff --git a/taglib/tag.h b/taglib/tag.h
index 76c9a82a..93bbfb15 100644
--- a/taglib/tag.h
+++ b/taglib/tag.h
@@ -64,9 +64,6 @@ namespace TagLib {
      * Removes unsupported properties, or a subset of them, from the tag.
      * The parameter \a properties must contain only entries from
      * properties().unsupportedData().
-     * BIC: Will become virtual in future releases. Currently the non-virtual
-     * standard implementation of TagLib::Tag does nothing, since there are
-     * no unsupported elements.
      */
     void removeUnsupportedProperties(const StringList& properties);
 
diff --git a/taglib/toolkit/tfile.cpp b/taglib/toolkit/tfile.cpp
index 8d7ccdc9..e6062199 100644
--- a/taglib/toolkit/tfile.cpp
+++ b/taglib/toolkit/tfile.cpp
@@ -119,120 +119,17 @@ FileName File::name() const
 
 PropertyMap File::properties() const
 {
-  // ugly workaround until this method is virtual
-  if(dynamic_cast<const APE::File* >(this))
-    return dynamic_cast<const APE::File* >(this)->properties();
-  if(dynamic_cast<const FLAC::File* >(this))
-    return dynamic_cast<const FLAC::File* >(this)->properties();
-  if(dynamic_cast<const IT::File* >(this))
-    return dynamic_cast<const IT::File* >(this)->properties();
-  if(dynamic_cast<const Mod::File* >(this))
-    return dynamic_cast<const Mod::File* >(this)->properties();
-  if(dynamic_cast<const MPC::File* >(this))
-    return dynamic_cast<const MPC::File* >(this)->properties();
-  if(dynamic_cast<const MPEG::File* >(this))
-    return dynamic_cast<const MPEG::File* >(this)->properties();
-  if(dynamic_cast<const Ogg::FLAC::File* >(this))
-    return dynamic_cast<const Ogg::FLAC::File* >(this)->properties();
-  if(dynamic_cast<const Ogg::Speex::File* >(this))
-    return dynamic_cast<const Ogg::Speex::File* >(this)->properties();
-  if(dynamic_cast<const Ogg::Opus::File* >(this))
-    return dynamic_cast<const Ogg::Opus::File* >(this)->properties();
-  if(dynamic_cast<const Ogg::Vorbis::File* >(this))
-    return dynamic_cast<const Ogg::Vorbis::File* >(this)->properties();
-  if(dynamic_cast<const RIFF::AIFF::File* >(this))
-    return dynamic_cast<const RIFF::AIFF::File* >(this)->properties();
-  if(dynamic_cast<const RIFF::WAV::File* >(this))
-    return dynamic_cast<const RIFF::WAV::File* >(this)->properties();
-  if(dynamic_cast<const S3M::File* >(this))
-    return dynamic_cast<const S3M::File* >(this)->properties();
-  if(dynamic_cast<const TrueAudio::File* >(this))
-    return dynamic_cast<const TrueAudio::File* >(this)->properties();
-  if(dynamic_cast<const WavPack::File* >(this))
-    return dynamic_cast<const WavPack::File* >(this)->properties();
-  if(dynamic_cast<const XM::File* >(this))
-    return dynamic_cast<const XM::File* >(this)->properties();
-  // no specialized implementation available -> use generic one
-  // - ASF: ugly format, largely undocumented, not worth implementing
-  //   dict interface ...
-  // - MP4: taglib's MP4::Tag does not really support anything beyond
-  //   the basic implementation, therefor we use just the default Tag
-  //   interface
   return tag()->properties();
 }
 
 void File::removeUnsupportedProperties(const StringList &properties)
 {
-  // here we only consider those formats that could possibly contain
-  // unsupported properties
-  if(dynamic_cast<APE::File* >(this))
-    dynamic_cast<APE::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<FLAC::File* >(this))
-    dynamic_cast<FLAC::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<MPC::File* >(this))
-    dynamic_cast<MPC::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<MPEG::File* >(this))
-    dynamic_cast<MPEG::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<Ogg::FLAC::File* >(this))
-    dynamic_cast<Ogg::FLAC::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<Ogg::Speex::File* >(this))
-    dynamic_cast<Ogg::Speex::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<Ogg::Opus::File* >(this))
-    dynamic_cast<Ogg::Opus::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<Ogg::Vorbis::File* >(this))
-    dynamic_cast<Ogg::Vorbis::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<RIFF::AIFF::File* >(this))
-    dynamic_cast<RIFF::AIFF::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<RIFF::WAV::File* >(this))
-    dynamic_cast<RIFF::WAV::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<S3M::File* >(this))
-    dynamic_cast<S3M::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<TrueAudio::File* >(this))
-    dynamic_cast<TrueAudio::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<WavPack::File* >(this))
-    dynamic_cast<WavPack::File* >(this)->removeUnsupportedProperties(properties);
-  else if(dynamic_cast<XM::File* >(this))
-    dynamic_cast<XM::File* >(this)->removeUnsupportedProperties(properties);
-  else
-    tag()->removeUnsupportedProperties(properties);
+  tag()->removeUnsupportedProperties(properties);
 }
 
 PropertyMap File::setProperties(const PropertyMap &properties)
 {
-  if(dynamic_cast<APE::File* >(this))
-    return dynamic_cast<APE::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<FLAC::File* >(this))
-    return dynamic_cast<FLAC::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<IT::File* >(this))
-    return dynamic_cast<IT::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<Mod::File* >(this))
-    return dynamic_cast<Mod::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<MPC::File* >(this))
-    return dynamic_cast<MPC::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<MPEG::File* >(this))
-    return dynamic_cast<MPEG::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<Ogg::FLAC::File* >(this))
-    return dynamic_cast<Ogg::FLAC::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<Ogg::Speex::File* >(this))
-    return dynamic_cast<Ogg::Speex::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<Ogg::Opus::File* >(this))
-    return dynamic_cast<Ogg::Opus::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<Ogg::Vorbis::File* >(this))
-    return dynamic_cast<Ogg::Vorbis::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<RIFF::AIFF::File* >(this))
-    return dynamic_cast<RIFF::AIFF::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<RIFF::WAV::File* >(this))
-    return dynamic_cast<RIFF::WAV::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<S3M::File* >(this))
-    return dynamic_cast<S3M::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<TrueAudio::File* >(this))
-    return dynamic_cast<TrueAudio::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<WavPack::File* >(this))
-    return dynamic_cast<WavPack::File* >(this)->setProperties(properties);
-  else if(dynamic_cast<XM::File* >(this))
-    return dynamic_cast<XM::File* >(this)->setProperties(properties);
-  else
-    return tag()->setProperties(properties);
+  return tag()->setProperties(properties);
 }
 
 ByteVector File::readBlock(ulong length)
diff --git a/taglib/toolkit/tfile.h b/taglib/toolkit/tfile.h
index 7e6f2b93..1dfab498 100644
--- a/taglib/toolkit/tfile.h
+++ b/taglib/toolkit/tfile.h
@@ -86,17 +86,15 @@ namespace TagLib {
      * format, the returend map's unsupportedData() list will contain one entry identifying
      * that object (e.g. the frame type for ID3v2 tags). Use removeUnsupportedProperties()
      * to remove (a subset of) them.
-     * BIC: Will be made virtual in future releases.
      */
-    PropertyMap properties() const;
+    virtual PropertyMap properties() const;
 
     /*!
      * Removes unsupported properties, or a subset of them, from the file's metadata.
      * The parameter \a properties must contain only entries from
      * properties().unsupportedData().
-     * BIC: Will be mad virtual in future releases.
      */
-    void removeUnsupportedProperties(const StringList& properties);
+    virtual void removeUnsupportedProperties(const StringList& properties);
 
     /*!
      * Sets the tags of this File to those specified in \a properties. Calls the
@@ -105,9 +103,9 @@ namespace TagLib {
      * If some value(s) could not be written imported to the specific metadata format,
      * the returned PropertyMap will contain those value(s). Otherwise it will be empty,
      * indicating that no problems occured.
-     * BIC: will become pure virtual in the future
      */
-    PropertyMap setProperties(const PropertyMap &properties);
+    virtual PropertyMap setProperties(const PropertyMap &properties);
+
     /*!
      * Returns a pointer to this file's audio properties.  This should be
      * reimplemented in the concrete subclasses.  If no audio properties were