Let's add a new word to the dictionary en-US.dic .
This word will be obout (our company name).

This word can not have any prefixes, and can have only one suffix: 's .
If we have a look at the [Suffix] section of en-US.dic file, we'll see that rules for this suffix have affix key M.
Now we generate the Phonetic code for the new word (see Generate phonetic code page), it will be *BT.

So we can add a new string to [Words] section of en-US.dic file:

      obout/M/*BT

This way you can add any names (companies and persons).

If the dictionary you update has an empty [Phonetic] section, then no Phonetic code should be added. In this case new string in [Words] section will have the following format:

       word/affix keys

NOTE.
Don't forget to restart your IIS after dictionary you used was updated.