How often have you come across forms that require you to enter your first name, middle initial, and last name? In the rest of the world, and to some extent in the USA, they may not work. The reason is that there are 2, not 3, major components to people's names:
1. Given-names: these are the names given to children by their parents (or, rarely, are changed by the children).
2. Family-names (otherwise known as surnames): these are the names passed down from generation to generation (except in Iceland).
Example 1: Mary Elizabeth Smith has two given-names and one family-name. If she calls herself Mary, then she has a first name, can use a middle initial, and has no problem with the forms.
Example 2: Supposing, however, that she has been called Elizabeth (Liz for short) since birth. Then, her name won't fit the standard forms. Neither will that of J. Edgar Hoover (a former FBI director) and many others. You can believe that Liz would not want to have to answer to the name Mary just because someone designed a form that records only her first name and middle initial.
Example 3. Liz Smith marries someone called Jim Brown. She may call herself Elizabeth Smith, or change her name to Elizabeth Brown, or Elizabeth Smith Brown. Her name Mary still is first, but she hardly ever uses it. So, what is now her "middle initial"?
Example 4: Ada María Guerrero Pérez is Mexican. Her names (nombres) are Ada María (and she always uses both these names), her primer apellido (father's family name) is Guerrero and her segundo apellido (mother's family name) is Pérez. You would find her in a Mexican phone book under "Guerrero Pérez, Ada María." She calls herself Ada María Guerrero. So what should she do when she encounters a US form asking for her "first name, middle initial, and last name"?
Example 5: Ada María marries someone called Alfonso Ernesto Hernández López. He has two given-names (and uses the second of these), and two family-names (Hernández and López). You find him in a Mexican telephone book under "Hernández López, Ernesto." He calls himself Ernesto Hernández. How does he respond to a US form asking for first name, middle initial, and last name?
Example 6: Ada María has new problems with US forms: after her marriage she is Ada María Guerrero de Hernández. So now how does she respond to a US form asking for first name, middle initial, and last name?
Example 7: Li Xiao Ping is from China. In China, Japan, Vietnam, Hungary, and some other countries, the family-name (Li) comes first. The two components (Xiao Ping) of his given name are used together as one name such that they could almost be written Xiaoping. You find him in a Chinese phone book as Li Xiao Ping (written in 3 chinese characters with no comma). How should he respond to a US form asking for first name, middle initial, and last name? Which of his names is last?
The design of US forms asking for "first name, middle
initial, and last name" is for the convenience of US designers
of forms. It assumes ignorantly that everyone's name fits this
mold, or imperiously that everyone's name must be forced into
this mold. It would be more appropriate to design forms to ask
for (a) given-names, and (b) family-names, and then (c) underline
the given-name and family-name by which you wish to be known.