Note: Url Blocking is only available to registered users of NetCaptor. Order NetCaptor.

Basic Concepts
Web pages, frames, iframes, images, javascript files and other types of web resources all generate HTTP requests to remote servers. NetCaptor's url blocking feature allows users to block these requests based on a "Block List". When url blocking is enabled, NetCaptor checks each HTTP request against its block list and intercepts and blocks requests that match the list. Url blocking can be used to block banner ads, images, web bugs, javascript files and any other resources which generate an HTTP request.

Block List
The block list is stored in a file called "block.dat" in the NetCaptor application directory. The block list is a simple text file. Each line in the file contains one block list item. The file is loaded at startup and stored in memory, and any changes made using the Options Dialog are written to disk at that time. Users should only edit the block list manually when NetCaptor is not running, because manual changes may be overwritten by NetCaptor.

NetCaptor only blocks items that are requested using the HTTP protocol. It is not necessary to add a 'http://' to the beginning of a block list item.

Case Sensitivity
Urls are converted to lowercase before they are checked against the block list, so all entries in the block list should be in lower case.

Wildcards
The block list supports two wildcards: * and ?. The * wildcard matches a string of any length. The ? wildcard matches a single character. To match against the end of a string, add a $ character to the end of your pattern. For example, to block all GIF images, add the pattern *.gif$. This will block all URL which end with the string '.gif'.

Block List Exceptions
Sometimes it may be helpful to have add an exception to the block list. This is accomplished by prepending $ to your block list entry. For example, you may want to block all Urls coming from the netcaptor.com, using a *.netcaptor.com block list entry. However, you may want to allow urls from www.netcaptor.com. To do so, add $www.netcaptor.com to your block list.