The following types of office uses may be preapproved in an office building: accounting, architectural, communication, computer, corporate headquarters, drafting, engineering, finance, scientific, mail or telephone sales, provided that the Planning Board first determines in writing that each such approved category of office use is unlikely to be accommodated in any of the Town's existing central or neighborhood business districts because of the nature of the activity or the amount of space required for the same. It is the intent of this section to permit only white collar facilities. In no case shall over-the-counter or other direct retail sales activities be permitted in any planned industrial park office, nor shall manufacturing or production activities of any kind be permitted. Further, walk-in offices catering to members of the general public or inviting such persons onto the premises for any purpose, such as brokerage offices, doctor's and lawyer's offices and the like shall in no case be permitted.