Dress shirt pockets are considered taboo across continental Europe for any shirt, casual, formal, or business, it does not matter. In other parts of the world a pocket is a normal addition to a business shirt.
At NiAlma we just want you to have the shirt that you want. If that means you like a pocket on your work shirt then have one. Especially if you use it to hold business cards or other small trinkets. Two button-down flap pockets on a casual shirt looks great.
The only dress shirt that simply cannot have a pocket is one you are designing for a formal or special occasion such as a wedding or dinner party. We do not recommend having a dress shirt pocket for these types of events.