see here for bold see here for italics subelement shows subcripts use sup elements to indicate something like a footer in your word document. An example of this is 9 in the list of footers. use this in order to highlight what you want. An example would be " I went to the store and bought water"
Using em element to put emphasis on certain words in the paragraph. Use the abbr format to abbreviate words such as DC and lastly use strong element to empower words