This bachelor's thesis deals with the design of fixes and improvements of available annotations editor and their implementation. The annotations editor for WYSIWYG text editors is created in JavaScript language and developed in the environment of TinyMCE editor. It is independent on a web browser and it will be possible to use it with other WYSIWYG editors like CKEditor or Aloha in future. The design is focused on manipulation with attributes of types but it also deals with the new concept of settings of annotations editor. The processing of suggested annotations that are sent by a server is also part of the solution. This thesis describes the design and implementation of mentioned improvements and pay attention to the possible ways of anot...