# Feature type These pages describe the single feature type ([BLPU (Type 21 Record)](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/os-emergency-services-gazetteer/os-esg-technical-specification/feature-type/blpu-type-21-record)) available for the OS Emergency Services Gazetteer (OS ESG). The attributes associated with the feature type are listed on the following page. The following information can be found about each attribute: ### Name and Definition The name of the attribute and what it is describing. ### Data Types The values the attribute can take. For example, a numeric value or a string. This is provided for both data formats – GeoPackage and CSV. ### Precision The maximum total number of decimal digits to be stored. This number includes both the left and the right sides of the decimal point. The precision must be a value from 1 through the maximum precision of 38. The SQL Server default precision is 18. ### Scale Scale (*s*) is the number of decimal digits that are stored to the right of the decimal point. This number is subtracted from precision (*p*) to determine the maximum number of digits to the left of the decimal point. Scale must be a value from 0 through *p*, and can only be specified if precision is specified. The default scale is 0 and so 0 <= *s* <= *p*. Maximum storage sizes vary, based on the precision. ### Code List Name The name of the code list used in association with the attribute (if applicable) and a hyperlink to the page displaying that code list. ### Max Length Values are given here to indicate the maximum length that you will find in the attribute, to aid in developing applications. ### Nullable A True or False value to denote whether the attribute always has to be populated with a value (False) or can be NULL (True). ### Data Schema Version The schema version the data above applies to.