Alternative alias convention

The standard convention numbers holes: 1, 2, 3, then 21, 22, 23 inside the 2. Some groups prefer letters instead. A manager can switch the whole map to an alphabetical scheme in Map settings → Mapping → Bookmark Format.

This only changes what the mapper suggests going forward — switching schemes never renames anything already on the map, and the two schemes can coexist on a map that's mid-switch.

The convention

Wormhole children extend the prefix with a letter: A → AA, AB, AC…; AB → ABA, ABB, ABC….
H, L, N and P are reserved and never used as a wormhole branch letter — the sequence skips them: …G, I, J, K, M, O, Q….
K-space exits use the reserved letter for their security class, plus a per-type index off the parent:

Class Pattern Example

High-sec <parent>H<idx> AH1, AH2

Low-sec <parent>L<idx> ACL1

Null-sec <parent>N<idx> BN2

Pochven <parent>P<idx> AP1
An unaliased home's direct holes get the empty-prefix case — A, B, C… — mirroring the numeric scheme's 1, 2, 3…. A manually-named root (e.g. naming your home A) works too, since a suggestion just extends whatever prefix already exists.
K-space exits can branch further: a wormhole found off AH1 suggests AH1A, exactly like any other wormhole child.
Freed letters are reused: with A, C and D on the map because the B was rolled and deleted, the next hole is suggested as B — same as the numeric scheme filling 2 between 1 and 3.

Class	Pattern	Example
High-sec	`<parent>H<idx>`	`AH1`, `AH2`
Low-sec	`<parent>L<idx>`	`ACL1`
Null-sec	`<parent>N<idx>`	`BN2`
Pochven	`<parent>P<idx>`	`AP1`

Example

The bookmark list inside an alphabetical A:

*A
AA ABC C3
AB XYZ C5
AH1 QWE 1DQ1-A Delve
AH2 RST J5A-IX Curse

AH1 and AH2 are two separate high-sec exits off A — the high-sec counter is independent per parent, so it doesn't collide with the wormhole letters AA/AB.

Known limitation

A single system with more than 22 direct wormhole children (there are only so many non-reserved letters) will start repeating the last suggestion, the same way the numeric scheme's suggestions become ambiguous past 9 children of one system.
Neither case is common enough to warrant a two-letter or multi-digit escape hatch.

Switching schemes

Only managers can change the scheme, in the same Bookmark Format card used to customize the bookmark template. The change is shared by everyone on the map, propagating live like the rest of that card's settings.