A method for updating personal information by a converged address book, CAB, extensible markup language, XML, document management server, XDMS, in a communication system supporting a CAB service, the method comprising: receiving a request to subscribe to an external personal profile information from a CAB client; providing information on the request to a CAB server; and storing changes in the external personal profile information that the CAB server is notified of from a non-CAB system by subscribing to the external personal profile information in the non-CAB system, as a new personal profile information document in response to an instruction from the CAB server, wherein the new personal information document includes an update type of the external personal profile information, wherein the update type includes a value indicating subscription of the external personal profile information, wherein the new personal information document includes an approval type of the external personal profile information, wherein the approval type denotes a 'manual' update or an 'automatic' update of the external personal profile information, and the 'manual' update or the 'automatic' update is set depending on a user preference for an update of the external personal profile information, wherein the method further comprises notifying changes in the external personal profile information to the CAB client, wherein, if the approval type denotes the 'manual' update, a reference link indicating a location in which the new personal profile information document is stored, is included in the new personal profile information document, and wherein the method further comprises: providing the new personal profile information to the CAB client using the reference link; receiving, from the CAB client, modified personal profile information including the changes selected by the CAB client, based on the notified changes and the new personal profile information received using the reference link; and updating the changes selected by the CAB client in the new personal profile information document. receiving a request to subscribe to an external personal profile information from a CAB client; providing information on the request to a CAB server; and storing changes in the external personal profile information that the CAB server is notified of from a non-CAB system by subscribing to the external personal profile information in the non-CAB system, as a new personal profile information document in response to an instruction from the CAB server, wherein the new personal information document includes an update type of the external personal profile information, wherein the update type includes a value indicating subscription of the external personal profile information, wherein the new personal information document includes an approval type of the external personal profile information, wherein the approval type denotes a 'manual' update or an 'automatic' update of the external personal profile information, and the 'manual' update or the 'automatic' update is set depending on a user preference for an update of the external personal profile information, wherein the method further comprises notifying changes in the external personal profile information to the CAB client, wherein, if the approval type denotes the 'manual' update, a reference link indicating a location in which the new personal profile information document is stored, is included in the new personal profile information document, and wherein the method further comprises: providing the new personal profile information to the CAB client using the reference link; receiving, from the CAB client, modified personal profile information including the changes selected by the CAB client, based on the notified changes and the new personal profile information received using the reference link; and updating the changes selected by the CAB client in the new personal profile information document. providing the new personal profile information to the CAB client using the reference link; receiving, from the CAB client, modified personal profile information including the changes selected by the CAB client, based on the notified changes and the new personal profile information received using the reference link; and updating the changes selected by the CAB client in the new personal profile information document.