Abstract: According to the invention, network code (for example, in HTML or XML) corresponding to a displayable portion of network content (such as an Internet Web site) is retrieved into a users' local processing system. A list of identifiers is then stored, by specific user choice, in the local system. Each identifier corresponds to a participating provider. In the user's local processing system, the network code is then parsed and any occurrence in the network code of any identifier stored in the list of identifiers is detected. For each detected identifier, a marker code is then inserted into the network code, the marker code indicating to the user the presence in the network code of each detected identifier. Both the network code and each inserted marker code are then displayed, whereby the presence in the network code of each detected identifier is made visible to the user. The identifiers include network address links and text strings.