揸打銀行的「揸打」是甚麼意思?

揸打 = Chartered = 特許的

Charters were the fundamental documents of the highly-structured, hierarchical system of Western feudalism. They were the instruments by which the possessor of a fiefdom (the lord) granted rights to vassals. This was typically for land, but might include anything, such as the right to incorporate a town or university, the right to hold a weekly market, or even the right to levy a toll on a road or bridge. There might be a payment specified or constraints applied, or the grant might be outright.
In UK, there maybe a Charter ganted by the Queen or Lord ( Royal Charter or Charter ) to Banks, Accountants, Surveyors etc. So, this word Charter is quite a restrictive word to represent a status of standing in UK. Chartered Bank is a bank from UK.