access: genesis of swarms from before the registry

Swarms started before the registry keep working without one; the
genesis node's options for a registry apply only to new swarms. What
tests and migration leave is noted in future-work.

Auth plan M1, bootstrap and migration (2.5).

1 files changed, 5 insertions, 8 deletions

diff --git a/docs/access.md b/docs/access.md
index b9e0296..cd11723 100644
--- a/docs/access.md
+++ b/docs/access.md
@@ -32,14 +32,11 @@ password hashes: every member reads the document).
 
 ## A new swarm
 
-Its genesis node records the first users, with the swarm ID, in its first change:
-
-* those of `--bootstrap-users`, each with everything (`[]` and `["_continuum"]`);
-* unset: the users of its `--htpasswd` with `[]`, and those of them, or of the
-  proxy's, in `--protocol-writers` with `["_continuum"]` too.
-
-A swarm nobody could manage doesn't start: with none of them with `["_continuum"]`,
-`--genesis` is refused, naming both options.
+A swarm gets a registry from its start if its genesis node is given its first users,
+`--bootstrap-users`: it records them, with the swarm ID, in its first change, each with
+everything (`[]` and `["_continuum"]`), and the other users of its `--htpasswd` with
+`[]`. Without it, the swarm has no registry, and is as swarms were before: users all
+alike (An existing swarm, below), until someone gives it one.
 
 ## At the HTTP API