1. A computer-implemented method of maintaining or managing a document obtained by a computing system operable to process and execute executable text in the document, the computer-implemented method comprising: marking the document, by a server, of text in the document as untrusted text to indicate that the text is not trusted or is not fully trusted via marked textual portions of the document, wherein a client device receives the marked document to identify the untrusted text in the document solely based on the document; wherein the marking of the untrusted text by the server comprises: marking the untrusted text by a hypertext markup language (HTML) extension to permit the client device to determine at least one action for the marked document, wherein the marking of the untrusted text comprises: providing in the document one or more attributes of the untrusted text, the attributes comprise one or more of a length attribute and an integrity attribute, and the integrity attribute is associated with an integrity value, the integrity value providing an indication of trustworthiness, and the length attribute is indicative of a length of untrusted text marked with a new HTML tag in a web page.
1. A computer-implemented method of maintaining or managing a document obtained by a computing system operable to process and execute executable text in the document, the computer-implemented method comprising: marking the document, by a server, of text in the document as untrusted text to indicate that the text is not trusted or is not fully trusted via marked textual portions of the document, wherein a client device receives the marked document to identify the untrusted text in the document solely based on the document; wherein the marking of the untrusted text by the server comprises: marking the untrusted text by a hypertext markup language (HTML) extension to permit the client device to determine at least one action for the marked document, wherein the marking of the untrusted text comprises: providing in the document one or more attributes of the untrusted text, the attributes comprise one or more of a length attribute and an integrity attribute, and the integrity attribute is associated with an integrity value, the integrity value providing an indication of trustworthiness, and the length attribute is indicative of a length of untrusted text marked with a new HTML tag in a web page. 9. The computer-implemented method of claim 1 , wherein the computer-implemented method further comprises performing by the client device the following steps to address propagation of tainted text: determining whether executable text in the document has been derived from, affected by, or derived from and affected by the untrusted text marked in the document; and identifying the executable text as untrusted text not to be trusted or not fully trusted when the determining determines that the executable text has been derived from, affected by, or derived from and affected by untrusted text in the document.