diff --git a/README.md b/README.md
index ad24098..7df9aa0 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,7 @@
 # TA-Proxmenu - Proxmox Scripts for TA Use
 
     bash <(curl -sL https://go.scity.us/install-tapm)
+
+To switch an installed main-branch copy to V2 for testing:
+
+    tapm V2
diff --git a/run.sh b/run.sh
index d61597d..ded2d16 100755
--- a/run.sh
+++ b/run.sh
@@ -5,6 +5,77 @@
 source /opt/idssys/defaults/default.inc
 source /opt/idssys/ta-proxmenu/defaults.inc
 
+SWITCH_TO_V2() {
+	local repository='/opt/idssys/ta-proxmenu'
+	local current_branch
+	local local_commit
+	local remote_commit
+
+	if [[ ! -d "${repository}/.git" ]]; then
+		echo -e "${idsCL[Red]}TA-ProxMenu is not a Git repository.${idsCL[Default]}"
+		return 1
+	fi
+
+	current_branch="$(git -C "$repository" branch --show-current 2>/dev/null)"
+	if [[ -z "$current_branch" ]]; then
+		echo -e "${idsCL[Red]}TA-ProxMenu is in a detached HEAD state; branch switching was refused.${idsCL[Default]}"
+		return 1
+	fi
+	if [[ "$current_branch" == "V2" ]]; then
+		echo -e "${idsCL[Green]}TA-ProxMenu is already using 'V2'.${idsCL[Default]}"
+		return 0
+	fi
+	if [[ -n "$(git -C "$repository" status --porcelain --untracked-files=normal)" ]]; then
+		echo -e "${idsCL[LightYellow]}TA-ProxMenu has local changes; branch switching was refused to preserve them.${idsCL[Default]}"
+		git -C "$repository" status --short
+		return 1
+	fi
+
+	echo -e "${idsCL[LightCyan]}Fetching TA-ProxMenu branch 'V2'...${idsCL[Default]}"
+	if ! timeout 30 git -C "$repository" fetch --prune origin \
+		'+refs/heads/V2:refs/remotes/origin/V2' >/dev/null 2>&1; then
+		echo -e "${idsCL[Red]}Could not fetch branch 'V2' from origin.${idsCL[Default]}"
+		return 1
+	fi
+
+	remote_commit="$(git -C "$repository" rev-parse --verify \
+		'refs/remotes/origin/V2^{commit}' 2>/dev/null)" || {
+		echo -e "${idsCL[Red]}Origin does not provide a usable V2 branch.${idsCL[Default]}"
+		return 1
+	}
+
+	if git -C "$repository" show-ref --verify --quiet refs/heads/V2; then
+		local_commit="$(git -C "$repository" rev-parse --verify \
+			'refs/heads/V2^{commit}' 2>/dev/null)" || return 1
+
+		if [[ "$local_commit" != "$remote_commit" ]] &&
+			! git -C "$repository" merge-base --is-ancestor \
+				"$local_commit" "$remote_commit"; then
+			echo -e "${idsCL[LightYellow]}Local branch 'V2' has local-only or diverged commits; switching was refused.${idsCL[Default]}"
+			return 1
+		fi
+
+		git -C "$repository" switch V2 >/dev/null || return 1
+		if [[ "$local_commit" != "$remote_commit" ]] &&
+			! git -C "$repository" merge --ff-only \
+				refs/remotes/origin/V2 >/dev/null; then
+			echo -e "${idsCL[Red]}Could not fast-forward V2; no commits were discarded.${idsCL[Default]}"
+			return 1
+		fi
+	else
+		git -C "$repository" switch --create V2 \
+			--track origin/V2 >/dev/null || return 1
+	fi
+
+	rm -f /var/cache/ta-proxmenu/update-status 2>/dev/null || true
+	echo -e "${idsCL[Green]}TA-ProxMenu is now using branch 'V2'.${idsCL[Default]}"
+}
+
+if [[ "${1:-}" == "V2" ]]; then
+	SWITCH_TO_V2
+	exit $?
+fi
+
 if [[ "${noupdate}" != *" ${1} "* ]] && [[ "${noupdate}" != *" ${2} "* ]]; then
   if curl -m 3 -s --head  --request GET https://git.scity.us | grep "HTTP/2 200" > /dev/null; then 
   	if [ "${1}" != "tapm" ]; then
@@ -68,4 +139,3 @@ if [ "${1}" != "tapm" ] && [ "${1}" != "update" ] && [ "${1}" != "u" ]; then
 fi
 
 exit 0
-