The dictionary assumes that all characters regardless what they are the appear after the previous white space character are part of the search query. This is most annoying when you are required to encapsulate some text in quotation marks.

For example

Typing "Main and pressing the Tab key will look for '"Main and will not list any matches, which would include Main Hand. And since it's two words separated by a space, without quotes /equip Main Hand will be interpreted as "equip Hand to slot Main."

So characters like ", (, etc need to be ignored when at the start of the string.

Items that end in +1, +2, etc, also are not appearing in the list.