Make sure we can see the most recent text. The remaining arguments RE are a regexps which matches text to be removed from the region. This function strips them out.
Counters are successive lines of text which display updated download transfer statistics, etc.
The remaining arguments RE are regexps which match the counter text to be updated in place. If called with a positive prefix argument, always enable. If called with a negative prefix argument, always disable. If called with no prefix argument, toggle current state. When a C-h character is seen in a buffer, delete that character as well as the previous character.