A domain name, or a pair of domain names, might be symmetrical in one of several ways.
Supported/Planned symmetries
| Type | Code | Example | Supported | Notes |
| Single Palindrome | a |
zb.snus.suns.bz |
Yes | zb.snus is suns.bz with letters in reverse order |
| Double Palindrome | |
su.suns.bz, zb.snus.us
(example domain we don't own) |
Yes | su.suns.bz is zb.snus.us with letters in reverse order |
| Single 180° Flip | b |
zq.suns.bz |
Yes | zq.su is ns.bz flipped 180° |
| Double 180° Flip | c |
zq.su, ns.bz
(example domains we don't own) |
Yes | zq.su is ns.bz flipped 180° |
| Single Mirrored DNS Components | |
com.example.www.example.com
|
Planned | Each domain name component is reversed |
| Double Mirrored DNS Components | e |
me.example.com, com.example.me
|
Yes | Each domain name component is reversed |
| Mirrored Text | d |
duq.xodbox.pub
(example domain we don't own) |
Planned | duq.xod is box.pub as read in a mirror |
| Double Mirrored Text | |
ood.pub, duq.boo
(example domains we don't own) |
Planned | ood.pub is duq.boo as read in a mirror |
Bonuses
We don’t do anything special with symmetries like this, but they’re neat.
| Type | Example | Supported | Notes |
| Palindrome URL | https://zb.snus.suns.bz//:sptth |
No |
https://zb.snus is the reverse of suns.bz//:sptth
|
| Palindrome Email | zb.snus@suns.bz |
No |
zb.snus is the reverse of suns.bz
|
| 180° Flip URL | https://zq.suns.bz//:sdʇʇɥ |
No |
https://zq.su is ns.bz//:sdʇʇɥ flipped 180°
(note non-ASCII :sdʇʇɥ)
|
| 180° Flip Email | zq.suns@suns.bz |
No |
zq.suns is suns.bz flipped 180°
|
| Mirrored Text Email | moc.elpmaxe@example.com |
No |
moc.elpmaxe is example.com as read in a mirror
|
| Antonymic DNS | https://at.example.email, https@example.website |
No |
Inspired by https://slashdot.org
|
Some mirrored or flipped symmetries are possible with non-ASCII characters,
but do not pass IDNA character validation.
For example, ɯoɔ.ǝldɯɐxǝ.example.com would be a neat flip,
and the browser will accept that as a domain name,
but it will translate it in the URL bar into punycode: https://xn--o-10a3f.xn--ldx-5ebd20eyg.example.com/,
which isn’t as fun.
Some of these non-ASCII characters are valid,
but finding them can be tricky.
To avoid homograph attacks,
where characters look the same but are not,
browsers have complicated rules for when characters are shown as Unicode or as punycode.
We encourage you tp spend as much time researching this as possible.
If you’re looking for more bonus points,
you might try to get the shortest possible flip as measured in either characters or domain name components.
At the time of this writing, for example, the valid ASCII 180° flip zznq.buzz is available!
Sure, it’s almost six thousand dollars,
but can you really put a price on winning a fake game on the Internet?