Why won't the index sort on the prefix word of a multiple word surname?
Reunion lets you instruct the index to "ignore" prefix words that are part of a surname. This option is set in the Indexing Options window shown below. To access this window, choose Options -> Indexing.
In the above illustration, Reunion has been instructed to ignore prefix words with less than 4 characters. Thus, an entry such as Van Dyke will be sorted in the D section.
If you prefer that Reunion not ignore prefix words, select Sort on the entire last name and click Rebuild Index. An entry such as Van Dyke will then be sorted in the V section.
It's possible you may have a mixture of names, some you want sorted on the prefix words, some you do not. If this is the case, you could configure the Indexing Options window as shown above and then use a non-breaking space character within names you want sorted based on the prefix word. A non-breaking space character is created by typing Option-space and has the same appearance as a regular space character. For example, if a non-breaking space is inserted between Van and Dyke, Reunion will see the entry as one word instead of two. It would then be sorted in the V section.
Click the Manual button and search for index for more details.