Let's add new word to 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 [Suffix] section of en-US.dic file, we'll see that rules for this suffix have affix key M.
Now we generate Phonetic code for the new word (see Generate phonetic code page), it will be *BT.

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

      obout/M/*BT

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

If dictionary you update has 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.