That's an interesting take. But it feels like an argument over semantics. So what would you call the requirement that my product parse iCal (RFC2445) instead

That's an interesting take. But it feels like an argument over semantics. So what would you call the requirement that my product parse iCal (RFC2445) instead of ignoring it and simply using the much more rationale Google Calendar GData API? I could ignore iCal. It'd marginalize me to less than 5% of the market. You could argue it's a decision and you'd be right. But it is a decision that constrains the success of my business. Hence "business constraint". What am I missing?