> ## Documentation Index
> Fetch the complete documentation index at: https://docs.loqate.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Match Rules

The syntax for a set of match rules is as follows:

```
<MatchRule>|<MatchRule>|…
```

The syntax for a match rule (`<MatchRule>`) is:

```
<Label>:<RuleDefinition>
```

Where `<Label>` is a free-text description to be associated with the particular rule. The syntax for the rule definition (`<RuleDefinition>`) is made up of a set of field searches which have the syntax:

```
<FieldName>,<SearchType>
```

where `<FieldName>` is the relevant field from the reference data and `<SearchType>` is one of:

* **LE** – Like Exact match, the input component must exactly match the reference data
* **LC** – Like Complete match, the input component must exactly match the initial substring from the reference data
* **LA** – Like Approx match, the input component must approximately (phonetically or textually) match the reference data
* **CE** – Contains Exact match, at least one word from the input component must exactly match at least one word from the reference data
* **CA** – Contains Approx match, at least one word from the input component must approximately (phonetically or textually) match at least one word from the reference data

## Combining Field Searches

Field Searches may be combined using the following syntax:

* `[]` means an optional component – it must match if it exists both in the input data and the reference data
* `()` encapsulates 'OR' component combinations
* `/` separates 'OR' component combinations

### Example

```
2:(PostalCodePrimary,LE/[AdministrativeArea,LE];Locality,LE/[AdministrativeArea,LE];DependentLocality,LE);Thoroughfare,CE;[PremiseNumber,LE]
```

which expanding the 'OR' components becomes:

```
2:PostalCodePrimary,LE;Thoroughfare,CE;[PremiseNumber,LE]

2:[AdministrativeArea,LE];Locality,LE;Thoroughfare,CE;[PremiseNumber,LE]

2:[AdministrativeArea,LE];DependentLocality,LE;Thoroughfare,CE;[PremiseNumber,LE]
```