diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 195255e..a0de6fb 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -82,6 +82,8 @@ jobs:
   version-bumped:
     name: Version bumped
     runs-on: ubuntu-latest
+    # Every pull request: ordinary work on a -DEV base keeps the version, and
+    # a release-branch backport on a released base must raise it (versions.py).
     if: github.event_name == 'pull_request'
     steps:
       - uses: actions/checkout@v6
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3371a34..b6a94c3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,25 @@ the next version with `-DEV`).
 
 ## [Unreleased]
 
+### Fixed
+- **PI stage: `initialize` no longer finishes on an unreferenced stage.** It
+  ignored the return of the reference move (`PI_FRF`), so when the controller
+  rejected it (GCS error 5, e.g. one axis's servo off) the later move to the
+  centre was rejected too and the driver believed the stage was centred while
+  the controller read about 0. It now checks `PI_FRF`, then polls `PI_qFRF`
+  for up to 60 s until both axes report referenced; either failure throws
+  with the `PI_GetError` code and closes the connection first, so a retried
+  `initialize` starts clean. `referencemove`'s signature and return are
+  unchanged. Reported by the MicroscopeAdapt rig; not yet run on hardware
+  (#64).
+
+### Changed (release process)
+- **`main` is the development branch**, carrying the next version with
+  `-DEV`; every pull request goes into it. The `0.3rc1` release-candidate
+  branch, which never released, is folded into `main` and retired, and CI's
+  version check runs on every pull request again. A release branch is cut only
+  for a safety backport (CLAUDE.md "Versioning").
+
 ## [0.2.4] - 2026-09-29
 
 Safety patch for the TCube laser driver. **v0.2.3 and every earlier tag are
diff --git a/CLAUDE.md b/CLAUDE.md
index fe3ef39..31f4b85 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -164,4 +164,25 @@ Some hardware modules are commented out in `MicroscopeControl.jl` while under de
 
 ### Versioning
 
-This package is 0.x and not yet registered; install a pinned tag per the README's Installation Notes. Policy, following Julia's pre-1.0 convention: while the version is `0.x.y`, **`x` is the breaking component and `y` is the non-breaking one** -- `0.2.0 -> 0.3.0` declares a breaking release and `0.2.0 -> 0.2.1` a compatible one, which is also how Julia's `^0.2` compat bound reads them. So bump `x` only when working downstream code can behave differently (a signature, an export, or what a call returns or throws), and bump `y` for everything else, including bug fixes that change behaviour on a path that was already broken. `.github/workflows/TagOnMerge.yml` tags a merge to `main` only when its Project.toml version is a release `X.Y.Z` (a `-DEV` version is development and is skipped, lab decision 0033) and a passing `lab/tests` record covers that commit's tree (decision 0009); an untested tree is not tagged, and the job says why. Hardware verification is not tracked in this repo; it is recorded by the downstream rig repo that pins to a given tag. The merge gate is the local suite (see "Testing policy" above) plus `test/contract.jl`'s "Interface Contract" testset, which guards the no-ambiguous-exports and core-method invariants described above; CI confirms it on a reduced matrix.
+This package is 0.x and not yet registered; install a pinned tag per the README's Installation Notes. Versions follow lab decision 0033.
+
+**`main` is the development branch.** Its `Project.toml` carries the next
+version with `-DEV`: after `vX.Y.Z` is tagged, the next pull request sets
+`X.Y.(Z+1)-DEV`. Every pull request goes into `main` and leaves that version
+alone, unless it breaks an interface, in which case it raises it to
+`X.(Y+1).0-DEV`. A release is one pull request that drops `-DEV` and writes
+the `CHANGELOG.md` section; `.github/workflows/TagOnMerge.yml` tags its merge
+`vX.Y.Z` when a passing `lab/tests` record covers that commit's tree
+(decision 0009), and otherwise fails and says why. It skips every `-DEV`
+merge. CI's "Version bumped" check runs on every pull request
+(`.github/scripts/versions.py`): against a `-DEV` base the version may stay
+or rise but never fall, and against a released base it must rise.
+
+A release branch exists only for a safety backport: when `main` has moved on
+to a breaking version and a rig pinned to the previous series needs a fix,
+cut `release-X.Y` from that series' last tag, merge the fix into it with a
+pull request that raises `Z`, and merge the same fix into `main`.
+`[limitation]` TagOnMerge watches `main` only, so a backport's tag is cut by
+hand, after checking the same `lab/tests` coverage.
+
+What the numbers mean (decision 0033): before 1.0, in `0.Y.Z` **raising `Z` is any non-breaking change, new features included, and raising `Y` is an interface break** -- `0.2.4 -> 0.3.0` declares a break and `0.2.4 -> 0.2.5` a compatible release, which is also how Julia's `^0.2` compat bound reads them. A break is anything that lets working downstream code behave differently: a signature, an export, or what a call returns or throws. A bug fix that changes behaviour only on a path that was already broken is not a break. Config types are built by keyword (lab decision 0035): adding a field with a default is not a break, and a positional argument's meaning never changes (add a keyword and deprecate the old form instead). Hardware verification is not tracked in this repo; it is recorded by the downstream rig repo that pins to a given tag. The merge gate is the local suite (see "Testing policy" above) plus `test/contract.jl`'s "Interface Contract" testset, which guards the no-ambiguous-exports and core-method invariants described above; CI confirms it on a reduced matrix.
diff --git a/Project.toml b/Project.toml
index 1f56ba2..50f08c3 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "MicroscopeControl"
 uuid = "aa70d9ae-4a1e-49fd-870a-8ccfd99f4c3e"
-version = "0.2.4"
+version = "0.2.5-DEV"
 authors = ["klidke@unm.edu"]
 
 [deps]
diff --git a/src/hardware_implementations/pi_stage/config_methods.jl b/src/hardware_implementations/pi_stage/config_methods.jl
index a2525b7..0d98669 100644
--- a/src/hardware_implementations/pi_stage/config_methods.jl
+++ b/src/hardware_implementations/pi_stage/config_methods.jl
@@ -42,13 +42,24 @@ function initialize_original(stage::PIStage) #TODO: Error handling
     #Set servo mode to on for both axes, noting axis X is labeled "1" and axis Y is labeled "2"
     servo(stage, true, true)
 
-    #Reference stage
-    referencemove(stage)
+    #Reference stage. A rejected FRF (e.g. GCS error 5, servo off on one axis) used to be
+    # ignored: every later PI_MOV was refused too, while the driver's cached position said
+    # the stage was centred. Refuse to come back from initialize unreferenced.
+    # On failure, close the connection so a retried initialize starts clean.
+    try
+        if referencemove(stage) != 1
+            error("PI_FRF refused (GCS error $(_pi_geterror(stage))); stage is not referenced")
+        end
+        _waitforreference(stage)
+    catch
+        shutdown_original(stage)
+        rethrow()
+    end
 
     #Find the max and min position of the axes
     getrange(stage)
-    
-    #Sleep 1 second for initialization
+
+    #Wait for any remaining motion to finish
     ismoving(stage)
     while stage.ismoving[1] == 1 || stage.ismoving[2] == 1
         ismoving(stage)
@@ -71,6 +82,27 @@ function referencemove(stage::PIStage)
     return ismoved
 end
 
+# PI_GetError returns and clears the controller's last GCS error code (0 = none).
+_pi_geterror(stage::PIStage) = @ccall gcs2path.PI_GetError(stage.id::Cint)::Cint
+
+"""
+Poll `PI_qFRF` until both axes report referenced; throw if that has not happened within
+`timeout` seconds or the query itself fails.
+"""
+function _waitforreference(stage::PIStage; timeout::Real = 60.0)
+    # PI_qFRF fills `BOOL*`: one 32-bit int per axis, like PI_SVO.
+    referenced = zeros(Cint, 2)
+    deadline = time() + timeout
+    while true
+        ok = @ccall gcs2path.PI_qFRF(stage.id::Cint, "1 2"::Ptr{UInt8}, referenced::Ptr{Cint})::Cint
+        ok == 1 || error("PI_qFRF failed (GCS error $(_pi_geterror(stage)))")
+        all(!=(0), referenced) && return nothing
+        time() > deadline && error("PI stage not referenced after $(timeout) s: " *
+            "qFRF = $(Int.(referenced)), GCS error $(_pi_geterror(stage))")
+        sleep(0.1)
+    end
+end
+
 
 """
 Function to disconnect PI Stage