More texty flags here.
Wiphala of Qulla Suyu, co-official flag of Bolivia since 2009, via. Thanks to Leonard Paul for the tip.
A lot of flags are easy to copy in textmode. But some of them have really nailed the textmode style: Bahrain, Belarus, Bosnia & Herzegovina, China (at sea), Czech Republic, Dominican Republic, Greece, USA, St Vincent & the Grenadines and Tonga (at sea). Via.