Tumblr: How do you hashtag in a caption?

[s t r a w b e r r y kisses]

Not the tag box itself, but the caption box. Like when people reblog things & add these hashtag comments. You know how people have a long string of broken up commentary hashtags in the caption box? How do you do that?

Like this: http://sherlylawks.tumblr.com/post/31286028994