A category may be associated, in a personal information manager (PIM) application, with a data item by associating a category pattern with the data item. Where the PIM application already associates keyword patterns with data items for enabling keyword searching, the category pattern may have a format of an ordered plurality of elements that satisfies at least one rule for the format of the keyword patterns. Optionally, the first element of the ordered plurality of elements may be an element predetermined to be specific to pluralities of elements associated with categories. Advantageously, this approach to the association of a category with a data item allows for the association of more than one category with a single data item. Such an allowance provides for more accurate synchronization with a PIM application on a desktop that also allows the association of more than one category with a data item. Given the allowance of the association of multiple categories with a single data item, the user may filter a list of data items by one or more categories.