15. A computer-program product, comprising: a computer readable storage medium storing one or more programs to be executed by a computer system, the one or more programs comprising: instructions to generate a link tag in a document, the link tag including a location value and one or more information pairs that are distinct from the location value, wherein a respective information pair has a respective parameter and a corresponding parameter value; and instructions to embed the link tag in the document; wherein the value in the embedded link tag specifies a method of processing content by a web crawler so as to modify information, associated with the content, that is being added to one or more databases used by a search engine, wherein the content to be processed is specified by the location value of the embedded link tag and the method of processing is in accordance with the respective parameter value in one or more of the one or more information pairs of the embedded link tag.
15. A computer-program product, comprising: a computer readable storage medium storing one or more programs to be executed by a computer system, the one or more programs comprising: instructions to generate a link tag in a document, the link tag including a location value and one or more information pairs that are distinct from the location value, wherein a respective information pair has a respective parameter and a corresponding parameter value; and instructions to embed the link tag in the document; wherein the value in the embedded link tag specifies a method of processing content by a web crawler so as to modify information, associated with the content, that is being added to one or more databases used by a search engine, wherein the content to be processed is specified by the location value of the embedded link tag and the method of processing is in accordance with the respective parameter value in one or more of the one or more information pairs of the embedded link tag. 16. The computer-program product of claim 15 , wherein an information pair of the one or more information pairs included in the embedded link tag is included in a second tag that includes the embedded link tag, the second tag includes a second information pair having a respective parameter and a corresponding second parameter value, and the selected method of processing content is performed on the content specified by the location value of the embedded link tag in accordance with the second parameter value.