Bold Text in Google Plus: If you want to write bold text, you must start your text with asterisk '*'and end with'*' for example *Bold Text* will appear as Bold Text.
Italic Text in Google Plus: If you want to write Italic text, you must start your text with underscore '_' and end with '_' for example _Italic Text_ will appear as Italic.
Strikethrough Text in Google Plus: If you want to write Strikethrough text, you must start your text with minus sign '-' and end with '-' for example -Strikethrough Text- will appear as Strikethrough Text.
Bold with Italic Text in Google Plus: In this case you must start your text with asterisk together with underscore '*_' and end with '_*' for example *_Bold with Italic Text_* will appear as Bold with Italic Text.
And now these work for youtube. great