I've recently been browsing vanilla servers and found that 99% of them are not whatsoever vanilla..... I've also seen people post that servers say "semi-vanilla" to me that is just saying its not vanilla at all. If it is vanilla it will have no plugins, no god mode if you tell the owner "Oh I want to build something cool" -.- , and no pre-built spawn. Just you spawning in a biome such as a forest with some people around you playing pure vanilla Minecraft.