Columns are named by stable serials over 9P, as panes are

/col/<n> named a column by its index, which shifts when a column left of it
closes: exactly what scripts trip on. A column is now /col/<serial>, its
serial kept while it lives and never reused; /layout lines give serial and
index (`<serial> <index> ...`), active names the serial, /index's last
field is the column's serial, and the log says newcol and delcol with
serials. Docs, the skill and the tree's README say so.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 12 insertions, 11 deletions

diff --git a/docs/fs.md b/docs/fs.md
index 5f382e7e..fd18d523 100644
--- a/docs/fs.md
+++ b/docs/fs.md
@@ -92,7 +92,7 @@ Existing Plan9port/v9fs clients need a userspace bridge for QUIC.
 
 ```
 /README      this guide, also src/fs-help.txt
-/index       one line per pane: serial, kind (text|term|pdf|image), dirty flag, name, column
+/index       one line per pane: serial, kind (text|term|pdf|image), dirty flag, name, column serial
 /status      pid, version and pane count
 /look        write a line: a right click on it at the active pane; read: the serials the last
              look, exec or ctl write touched (made, else acted at)
@@ -105,10 +105,10 @@ Existing Plan9port/v9fs clients need a userspace bridge for QUIC.
 /focus       the serial of the pane with the keyboard; write a serial to give it the keyboard
 /ctl         the settings, one a line as a write takes them; write a setting or a session builtin
 /commands    every builtin: word, `arg` if it takes one, `root` or `pane` (the ctl that takes it), a setting's values
-/layout      one line per column: index x width current|notcurrent empty|full serials...;
-             then active <index> (- when no column has the keyboard)
+/layout      one line per column, left to right: serial index x width current|notcurrent
+             empty|full pane-serials...; then active <serial> (- when no column has the keyboard)
 /tag         the workspace tag; > replaces it, >> appends, one line
-/col/<n>/tag column n's tag, the same way; columns count from 0, left to right
+/col/<n>/tag the tag of the column with serial n, the same way
 /pane/new    open it to make a pane; the read answers that pane's serial
 /pane/<n>/   name body tag ctl addr dot limit data xdata sel dirty mark scroll
              errors event look exec, plus pty/{ctl,status,data} on terminals
@@ -118,13 +118,14 @@ Existing Plan9port/v9fs clients need a userspace bridge for QUIC.
 
 `/layout`, `/tag` and `/col` go past acme, which serves no column files --
 its columns are only where a window sits. They are here so a script can see
-where the panes are (`/index`'s last word is each one's column, the same
-index) and edit the tags a person clicks in: a column tag is one line, a
-newline written into it a space, and a truncating write (`echo Make >
-col/0/tag`) clears it and drops the newline that ends it, as a pane tag's
-does. A column is named by its index, so the columns right of one that
-closes move down one; the log says `newcol <n>` and `delcol <n>` as they come
-and go, with /layout to read again.
+where the panes are (`/index`'s last word is each one's column serial) and
+edit the tags a person clicks in: a column tag is one line, a newline
+written into it a space, and a truncating write (`echo Make > col/3/tag`)
+clears it and drops the newline that ends it, as a pane tag's does. A
+column is named by its serial, as a pane is: it stays while the column
+lives, whatever opens or closes beside it, and is never reused; /layout
+gives each column's serial and its index left to right, and the log says
+`newcol <serial>` and `delcol <serial>` as columns come and go.
 
 Control messages are split by what they act on, as acme keeps window verbs
 on a window's ctl and webfs and upas/fs keep session settings on a root ctl.