Strange icon on notification bar of Samsung Galaxy Note 3

I couldn't find the meaning of the icon HD (the letters "HD" are surrounded by a shape like a text messenger icon). Please help me. Thanks in advance.

Attached Images

• Screenshot_2016-12-31-16-37-54.png (789.1 KB)

from Android Forums at AndroidCentral.com - Ask a Question //forums.androidcentral.com/ask-question/758202-strange-icon-notification-bar-samsung-galaxy-note-3-a-new-post.html
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