Using Wildcards in Category Rules

Wildcards can be added to concepts in rules in order to extend the matching capabilities. The asterisk * wildcard can be placed before and/or after a word to indicate how concepts can be matched. There are two types of wildcard uses:

Affix wildcards. These wildcards immediately prefix or suffix without any space separating the string and the asterisk. For example, operat* could match operat, operate, operates, operations, operational, and so on.
Word wildcards. These wildcards prefix or suffix a concept with a space between the concept and the asterisk. For example, * operation could match operation, surgical operation, post operation, and so on. Additionally, a word wildcard can be used along side an affix wildcard such as, * operat* *, which could match operation, surgical operation, telephone operator, operatic aria, and so on. As you can see in this last example, we recommend that wildcards be used with care so as not to cast the net too widely and capture unwanted matches.

Exceptions!

A wildcard can never stand on its own. For example, (apple | * ) would not be accepted.
A wildcard can never be used to match type names. <Negative*> will not match any type names at all.
You cannot filter out certain types from being matched to concepts found through wildcards. The type to which the concept is assigned is used automatically.
A wildcard can never be in the middle of a word sequence, whether it is end or beginning of a word (open* account) or a standalone component (open * account). You cannot use wildcards in type names either. For example, word* word, such as apple* recipe, will not match applesauce recipe or anything else at all. However, apple* * would match applesauce recipe, apple pie, apple and so on. In another example, word * word, such as apple * toast, will not match apple cinnamon toast or anything else at all since the asterisk appears between two other words. However, apple * would match apple cinnamon toast, apple, apple pie and so on.

Table 1. Wildcard usage
Expression	Matches a document or record that
`*apple`	Contains a concept that ends with letter written but may have any number of letters as a prefix. For example: `apple` ends with the letters apple* but can take a prefix such as: - `apple` - `pineapple` - `crabapple`
`apple*`	Contains a concept that starts with letters written but may have any number of letters as a suffix. For example: `apple` starts with the letters apple* but can take a suffix or no suffix such as: - `apple` - `applesauce` - `applejack` For example, `apple* & !(pear* \| quince)`, which contains a concept that starts with the letters `apple` but not a concept starting with the letters pear or the concept `quince`, would NOT match: `apple & quince` but could match: - `applesauce` - `apple & orange`
`product`	Contains a concept that contains the letters written `product`, but may have any number of letters as either a prefix or suffix or both. For example: `product` could match: - `product` - `byproduct` - `unproductive`
`* loan`	Contains a concept that contains the word `loan` but may be a compound with another word placed before it. For example, `* loan` could match: - `loan` - `car loan` - `home equity loan` For example, `[* delivery + <Negative>]` contains a concept that ends in the word `delivery` in the first position and contains a type `<Negative>` in the second position could match the following concept patterns: - `package delivery + slow` - `overnight delivery + late`
`event *`	Contains a concept that contains the word `event` but may be a compound followed by another word. For example, `event *` could match: - `event` - `event location` - `event planning committee`
`* apple *`	Contains a concept that might start with any word followed by the word `apple` possibly followed by another word. `` means 0 or n, so it also matches `apple`. For example, ` apple ` could match: - `gala applesauce` - `granny smith apple crumble` - `famous apple pie` - `apple` For example, `[ reservation* * + <Positive>]`, which contains a concept with the word `reservation` (regardless of where it is in the concept) in the first position and contains a type `<Positive>` in the second position could match the concept patterns: - `reservation system + good` - `online reservation + good`

Note: For examples of how rules match text, see Category Rule Examples