1. A method of implementing non-schema attributes for objects in a directory enforcing schema control on object attributes comprising: storing a plurality of objects in a computer-implemented directory in accordance with a pre-defined schema for the directory, wherein the pre-defined schema specifies objects permitted in the directory and a plurality of attributes for the objects including one or more multivalue attributes, wherein each multivalue attribute includes an attribute name and multiple value portions each associated with that attribute name; encoding in the form of a string each of a plurality of non-schema attributes for an object in the directory, wherein the non-schema attributes are not defined in the pre-defined schema and each encoded string for a non-schema attribute includes a first portion with a name for that non-schema attribute and a second portion with a value for that non-schema attribute, and wherein the plurality of non-schema attributes includes at least two different non-schema attributes with different names; embedding each of the encoded strings for the non-schema attributes in a different value portion of a multivalue attribute of the object specified in the pre-defined schema without modification of the pre-defined schema to include definitions for the non-schema attributes, wherein the multivalue attribute contains the names and values for the plurality of non-schema attributes including the at least two different non-schema attributes, and wherein a syntax specifying a format for a corresponding non-schema attribute is maintained in a different multivalue attribute for the object in the pre-defined schema and the different multivalue attribute includes a name for the corresponding non-schema attribute and the syntax specifying a format for the corresponding non-schema attribute; and performing operations on the non-schema attributes of the object by accessing values of the non-schema attributes based on the names within the encoded strings in the value portions of the multivalue attribute.