Understanding Outlook User-Defined Fields (part 1)

This will be presented in three parts with the objective being to outline how to minimize potential problems when sharing information between Outlook and other programs, particularly when it comes to user-defined fields. If you do not plan on sharing information between Outlook and another program, then this article will be of little interest. However, it is always good to keep in mind that the decisions made today on the basis that you are not currently sharing data will remain in effect tomorrow if the need does arise.

Part one focus is on the construct of the field name itself or more specifically what characters should be used to minimize problems.

Part two will focus on “why it matters”

Part three will focus on how to retain all the flexibility you want in terms of how you “see” the field names versus how other programs have to deal with it.

Outlook provides <almost> complete flexibility when it comes to creating user-defined field names allowing characters in a field name that are not deemed valid by database systems, and not every database/file system has the same rules.

To virtually guarantee that any user-defined field names are 100% compatible with any and all file systems, you just need to follow one simple and very basic rule which is:

Create field names that only contain alphanumeric characters (A-Z, a-z, 0-9) with no spaces or special characters of any kind (such as a single quote etc), do not use spaces and are preferably no longer than 32 characters. No more – no less.

The reason for this is a very simple one. A generic field name will not depend on any other program having to make adjustments for what are considered illegal or special characters. While the reaction may be that you, the user, shouldn’t have to worry about or deal with something like that is valid to a point but that doesn’t alter the primary objcetive of minimizing potential problems.

To provide some simple comparitive examples:

Characters considered illegal in Outlook when defining a user-defined field name are:

  • “[” – left square bracket
  • “]” – right square bracket
  • “_” – underscore
  • “#” – number/pound sign
    (all other characters are considered valid)

Characters considered illegal for an Microsoft Access field name are:

  • ” ” – leading space
  • “.” – period
  • “`” – accent
  • “[” – left square bracket
  • “]” – right square bracket
  • (”) – double quote character
  • “!” – exclamation point
  • - any unprintable character

Ironically, a very common character used in the creation of database field name is the “underscore” ( _ ) character which is not a legal character in Outlook.

Many people seem to like (or are under the impression) that field names in files need to/should be identical when importing. This is not the case but as the simple list above shows, it may be impossible depending on what characters are used in the creation of the Outlook field name.