1. A computer-implemented method for managing global annotations for data elements present in a data source comprising: defining a set of data elements capable of being annotated with a global annotation, wherein each global annotation is stored by an annotation system independently from a representation used by a plurality of software applications to represent a particular data element; identifying the data source accessed by a user, wherein the data source includes a plurality of data elements; parsing, by the annotation system, the data source to identify a set of candidate data elements from the plurality, wherein parsing the data source to identify a set of candidate data elements comprises transforming the data elements appearing in the data source to a normalized form used by the annotation system to identify data elements independently from a representation used by a software application for a particular data element and comparing the normalized data elements with the set of data elements capable of being annotated with a global annotation, and wherein each member of the set of candidate data also appears in the set of data elements capable of being annotated with a global annotation; returning an indication of the members of the set of candidate data elements to the software application; receiving, from one of the plurality of software applications, a request to create a global annotation for one of the candidate data elements; selecting an annotation structure that defines a set of fields required to create the global annotation; obtaining annotation content for a new global annotation; populating the annotation structure with the annotation content; and storing, by the annotation system, the created global annotation in the normalized form for the candidate data element.