diff --git a/Programs/CosmOS/Source/cosmos.asm b/Programs/CosmOS/Source/cosmos.asm
index 13525f6..73ab0be 100644
--- a/Programs/CosmOS/Source/cosmos.asm
+++ b/Programs/CosmOS/Source/cosmos.asm
@@ -5568,8 +5568,6 @@ MonitorPrompt:
 UnknownText:
 "       ?
 "
-MonitorName:
-"monitor"
 MonitorHelp:
 "x examine, d disassemble, a assemble, s set, b bank, g go, exit leaves"
 ExamineName:
@@ -5604,6 +5602,17 @@ NoSuchOp:
 "no such instruction"
 NeedsValue:
 "that one needs a value after it"
+; ---- The shell's own words, packed ----
+;
+; Fifteen names with nothing between them, which is a TABLE and not an accident of layout.
+; Each is a string ending in a zero, so the next one begins after that zero and walking them
+; needs no pointers and no lengths - which is what makes completing a half typed command
+; possible at all, since the dispatch below is a chain of comparisons and cannot be walked.
+;
+; NOTHING MAY BE PUT BETWEEN THEM. Tests/docs.sh checks that this run holds exactly the names
+; the dispatch tests and that the count below agrees, so a command added without a name here
+; is caught rather than silently left out of what Tab knows about.
+ShellNames:
 DirName:
 "dir"
 DoName:
@@ -5632,6 +5641,12 @@ HelpName:
 "help"
 ExitName:
 "exit"
+MonitorName:
+"monitor"
+
+; How many of them, since a run of strings does not say where it stops.
+ShellNameCount:
+  0d15
 
 ; Where the machine is, written out for the prompt, and where in the buffer it begins.
 ; Built from the end backwards, so it starts somewhere in the middle.
diff --git a/Tests/docs.sh b/Tests/docs.sh
index 7ee3d2f..d968493 100755
--- a/Tests/docs.sh
+++ b/Tests/docs.sh
@@ -456,6 +456,50 @@ for name, text in (("the Programming Manual", pm), ("the Assembler Manual", am),
             problems.append("%s still says \"%s\", and it has not been true since"
                             " directories arrived" % (name, claim))
 
+# ---- The shell's words are a table as well as a chain of comparisons ----
+#
+# The dispatch is a run of "is the line this name" tests, which is fine to execute and
+# impossible to WALK - so completing a half typed command needs the names as data too, and
+# they are: fifteen strings packed end to end from ShellNames, each ending in the zero that
+# says where the next begins.
+#
+# THE TWO CAN DISAGREE AND THE WAY THEY DO IS QUIET. A command added to the dispatch and not
+# to the run simply never completes, which nobody would think to test by hand; something put
+# BETWEEN the strings ends the walk early and takes the rest of the commands with it. So this
+# reads both and compares them, and reads the count as well, because a run of strings does
+# not say where it stops.
+cosmosSource = open("Programs/CosmOS/Source/cosmos.asm").read()
+
+# The dispatch, up to the point where the monitor's single letters begin - those are one
+# character each and there is nothing to complete about them.
+dispatchEnd = cosmosSource.find("SETD.0 Mode")
+dispatched = re.findall(r"SETD\.1 (\w+Name)\b", cosmosSource[:dispatchEnd])
+
+# The run, which ends at the first thing that is not a label and a string.
+runAt = cosmosSource.find("ShellNames:")
+packed = []
+if runAt < 0:
+    problems.append("cosmos.asm has no ShellNames run for the shell's own words")
+else:
+    lines = cosmosSource[runAt:].split("\n")[1:]
+    while len(lines) >= 2 and re.fullmatch(r"(\w+Name):", lines[0]) \
+            and re.fullmatch(r'"[^"]*"', lines[1]):
+        packed.append(lines[0][:-1])
+        lines = lines[2:]
+
+stated = re.search(r"ShellNameCount:\s*\n\s*0d(\d+)", cosmosSource)
+if not stated:
+    problems.append("cosmos.asm no longer says how many shell names there are")
+elif int(stated.group(1)) != len(packed):
+    problems.append("cosmos.asm says there are %s shell names and the run holds %d"
+                    % (stated.group(1), len(packed)))
+if runAt >= 0 and sorted(packed) != sorted(dispatched):
+    missing = sorted(set(dispatched) - set(packed))
+    extra = sorted(set(packed) - set(dispatched))
+    problems.append("the shell's dispatch and its packed names disagree:%s%s"
+                    % ("".join(" %s is dispatched and not in the run;" % n for n in missing),
+                       "".join(" %s is in the run and not dispatched;" % n for n in extra)))
+
 # ---- CosmOS fits in the half of the machine it says it does ----
 #
 # The memory map in the CosmOS README is a CONVENTION. Nothing in the assembler, the