# also assumes that the parentheses are not in the filename
/<img           # match the '<img'
 \s+            # must have one or more whitespace characters
 src            # match the 'src'
 \s*            # may have zero or more whitespace characters
 =              # match the =
 \s*            # may have zero or more whitespace characters
 [^-]+          # one or more non-dash characters
 -disclose.gif  # rest of .gif name
 [^>]*          # zero or more non-closing angle brackets
 >/ix           # closing angle bracket