Since a guild website is NOT connected to the game, I fail to understand why people are stating to check a website.
It is common to be able to see who was invited, by whom, when, who left, got kicked etc. And if you have a guild with even as few as say 75 members and can remember every single person then grats to you. Frankly I don't have the time to try and memorize something like this (nor do I want to), which is why a guild log needs to be implemented.