If you have sufficient privileges, you can use the Annotation toolbar to add annotations to text and image documents including highlights, arrows, ellipses, and overlapped text.
Note:
Depending on your system's configuration, redaction annotations may be available in the annotations list. Redaction annotations are not supported for creating permanent redactions, but they can be used to create temporary redactions for the purpose of printing a redacted document. To permanently redact a document, see Redacting a Document.
To create and place an annotation on a text or image document: