dataflown

Of course unsigned is defined. That's besides the point. The point is: how often in your code, do you expect 1 minus 2 to equal a very large number, vs. the number -1.

No. It says the reverse: "11. unsigned. Use unsigned if necessary."

Unsigned is necessary only if you're working with bit fields, bit masks or require explicit modulo n-bit arithmetic.

For all other cases, use signed

Actually, in that case, no.

Blogger hasn't bothered to refer to those well known and detailed opinions, from very experienced authorities, and provide detailed rebuttal to those authorities claims, so his opinion can be safely ignored.

Stroustrup recommends int over unsigned. Dijkstra recommends int over unsigned. Google coding guidelines recommend int over unsigned.

Blogger recommends unsigned over int.

Tough choice.