You specify a person's name in the field in the Main tab of the Property Box (see How to View an Individual's Record in the Property Box). When you enter a person's name that consists of more than one word, Family Historian will always assume that the last name is the surname, unless you explicitly indicate otherwise by using slash characters to mark the surname. Suppose, for example, that Elizabeth Powell Smith's surname is 'Powell Smith'. If you entered her name simply as "Elizabeth Powell Smith", Family Historian would assume that 'Smith' was the surname. To mark her surname correctly you would need to put slashes round 'Powell Smith' like this: "Elizabeth /Powell Smith/". If the name had been hyphenated however (as 'Powell-Smith') there would have been no need for slashes as Family Historian would have treated the hyphenated name 'Powell-Smith' as the last name, and hence the surname.
In some languages, the surname may not necessary appear at the end of the name. For example, "Mao Tse-Tung" should be entered as "/Mao/ Tse-Tung" because 'Mao' is the surname. If you only enter only one word as the name (e.g. 'Jane') Family Historian will, by default, assume that it is not the surname and will automatically add two slash characters on the end of the name to reflect this ("Jane //"). If actually 'Jane' was the surname, and that's the only name you had, you would need to enter it as "/Jane/" to make this clear. Of course, the alternative is to use a question mark or something similar, to mark the unknown name part - for example, "Jane ?" or "? Jane".
Why does Family Historian need to know which part of the name is the surname? It needs to know this so that it can provide a number of different services, such as automatic capitalization of surnames, surname-first ordering, search-by-surname, and much more.
When viewing names in Name fields, for editing purposes, Family Historian can, if you wish, always put slashes round the surname, to make it clear which part of the name is the surname. However, for aesthetic reasons, Family Historian by default keeps the use of slashes to a minimum, and only puts slashes round the surname when this is needed for clarity - that is, if the surname is not the last name, or if there is only one word in the name. See the Show Surnames Between Slashes option in Preferences: Property Box tab for options relating to this.
Other points:
Enter each person's name in the normal order in which it is given in their culture. So, for example, in the West, the surname normally appears at the end of the name; consequently, "Arthur Boyd Smith" should be entered as "Arthur Boyd Smith" (without the quotes) and not as "Smith, Arthur Boyd".
We recommend that you do not enter the surname in upper case. It will, by default, be displayed in upper case in diagrams, reports and elsewhere anyway; but you should enter it (and all other parts of the name) in mixed case as it would normally be written. For example, the surname McCracken should be entered as shown.
If you don't know a person's surname, enter the names you do know, but put two slashes at the end to show that the last name is not the surname - for example, "John Peter //". If you prefer, you can instead put a question mark, or perhaps "(unknown)", instead of the slashes, to mark where the surname should be.
Use maiden names for women. See also How to Record a Woman's Married Name.
If you want to record a nickname, or an alternative name, or specify which given name a person used, or record their titles, see How to Record Alternative Names, Nicknames, Titles, etc . There is no limit to the number of names that you can record for a person.