The regular expression

   /^Dr|Lady|Lord|Miss|Mr|Mrs|Ms|Sir|$/
[download]

matches like the following separated regular expressions:

/^Dr/ or /Lady/ or ... or /Sir/ or /$/
[download]

... which, obviously is not what you want. What you want is to group all the alternative titles together and make sure that there is only the title in the string:

    /^(?:Dr|Lady|Lord...|Sir|)$/
[download]

The noncapturing group (?:...) makes sure that the alternatives only extend within it, so the two anchors ^ and $ still anchor the whole string.