xkcd #3307: Spectrum Allocation
Title text:
Rumor has it that they're finally auctioning off the zeppelin navigation bands, but everyone is worried that the scary boat captains will express interest.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3307/
If you want to see the real chart... (For the US at least)
NTIA Frequency Allocations