Now that you have taken the person’s name in a single text field, the same problems mean that you can’t intelligently split it into parts, so don’t even try.

If you really think you “need” a “first” name for addressing the person in communications, a more correct thing to do is have a separate text field for “preferred name”, or “preferred form of address”.

The preferred form of address may differ depending on the level of formality of the message you send to them. For example, if your communications are written casually, a person might choose to be addressed as “John”, whereas if your communications are written more formally, the same person might choose to be addressed as “Mr. Smith”. So make sure you make it clear which formality will be used, perhaps by showing an example of the top of the email you would send out.

Prefixes and suffixes are an interesting case of this. While removing some prefixes or suffixes doesn’t change the name, this is not always the case. A particularly obvious case of this is the suffix “Jr.”, where removing the suffix would result in naming the person’s parent.

• Fallacy 14: People’s names sometimes have prefixes or suffixes, but you can safely ignore those.