Precedence in the matrix

A defining feature of HTTP Switchboard is the precedence/graylisting/inheritance concept in the matrix.

A "graylisted" matrix cell (pale green or pale red) means the cell inherits its allow or block status from a higher precedence cell in the matrix.

This feature allows the user to whitelist or blacklist a whole group of cell with a single click on a higher precedence cell in the matrix. Here is the tree list of precedence/inheritance of the matrix, from highest to lowest:

• The all cell (top-left corner of the matrix)
  • Types cells (i.e. cookie, css, img, etc.)
    • Specific type and specific domain names (i.e. css/wikipedia.org, img/wired.com, etc.)
      • Specific type and specific subdomain names (i.e. css/en.wikipedia.org, script/www.facebook.com, etc.)
  • Domain name cells (i.e. wikipedia.org, facebook.com, wired.com, etc.)
    • Subdomain name cells (i.e. en.wikipedia.org, www.facebook.com, video.wired.com, etc.)
      • Specific type and specific subdomain names
    • Specific type and specific domain names
      • Specific type and specific subdomain names

Any explicit whitelist or blacklist status of a cell will cascade down through inheritance to the graylisted cells in the next level. Ultimately, this means that it is possible to control all the cells in the matrix with just the top-left all cell.

Now if you've understood the above tree list, you may have noticed that a single graylisted cell in the middle of the matrix may inherit from two different ancestors: the hostnames (left column) or the type (top row). It is up to the user to choose how this double inheritance works by disabling or enabling "strict blocking (on the Settings page):

• "Strict blocking" disabled: The status of the hostname has precedence over the type in deciding the inherited status of a cell.
• "Strict blocking" enabled: A cell will be whitelisted only if both the hostname and the type are not blacklisted.

"Strict blocking" is strongly recommended for security conscious users.

[to do: many animated GIF to illustrate the above]