Adobe Lightroom 2.0 Beta included a new feature called Smart Collections. These collections are created automatically after setting some rules. The rules are very customizable and can filter based on certain data from your images. There is a trick to filtering for some words though that are contained within other words. If not properly entered in the filter, the smart collection will contain images that were not intended to be included.
When setting up a rule to filter on a word that is short, not very unique and can be part of other words, there is trick to follow. Take the example of a keyword ‘rob’ which is also contained in ‘robby’, ‘robert’, ‘throb’ and ‘robin’. Simply setting the smart collection to contain ‘rob’ will filter in a lot of other images that were not desired.
The trick (or rather rule) is this: use the ‘+’ sign in your filter text. The ‘+’ sign, or plus sign, indicates either starts with or ends with depending on whether you place it at the beginning of a word or the end.
Thus, to filter out ‘throb’ in our example, use ‘+rob’ as the filter. This will leave ‘rob’, ‘robby’, robbert’ and ‘robin’. To filter out everything except ‘rob’, use the ‘+’ sign at both the beginning and the end. Thus, ‘+rob+’ will filter out ‘robby’, ‘robbert’ and ‘robin’ in addition to ‘throb’. Reading the translation of the filter you get ‘starts with rob and ends with rob’.
Hope this helps!