Use the Toolbar to Work with Comments
You can use the toolbar to work with comments in the Conversations tab. The toolbar provides several frequently used features, like adding headings, boldface, italics, or strikethrough text; adding quotes, code, links, or lists; or attaching files or images to comments. This reduces or eliminates the need for using markdown directly to work with those items, although you certainly can still write and edit comments using markdown.
- In the Write tab, add some text to a
comment then use the toolbar to format the text, insert
links, create lists, or add files or images you've
uploaded.
These are the icons you can use in the toolbar:
Icon Description 
Click the Heading icon to create a heading (or add subheadings that can be nested). 
Click the Bold icon to enter text that appears in boldface. 
Click the Italics icon to enter text that appears in italics. 
Click the Strikethrough icon to make the text you enter appear with a line through it. 
Click the Quote icon to enter text in quotation marks. 
Click the Code icon to indicate that the text is code, not plain text. 
Click the Link icon to enter a link to a URL. 
Click the Unordered List icon to create a bulleted list. 
Click the Ordered List icon to create a numbered list. 
Click the Task List icon to create a specialty list where tasks can be checked off as they are completed. This option may not be supported by all markdown types. 
Click the Attach a file or image icon to add an uploaded screen shot, image, or file to a comment. See Add an Attachment (Image or File) to a Merge Request Comment for information about using the toolbar to add attachments (screen shots, images, and files) to comments.