The actual feature is 'Add me to active users list' when logging-in
The reason why the text says this is I tried both ways, I did have it as 'Browse the board annoymously' and when selected the user was shown as off-line as well as being anonymous in the active users list. People then complained it was a bug and demanded that the user be shown as on-line.
The feature was then changed to 'Add me to active users list' so they are still shown as on-line but they are listed in the active users list as Anonymous.
I would have thought your member being a lawyer would be well used to 'reading between the lines' when it comes to wording