diff --git a/crates/aura-cli/src/campaign_run.rs b/crates/aura-cli/src/campaign_run.rs
index f103304..15fe8de 100644
--- a/crates/aura-cli/src/campaign_run.rs
+++ b/crates/aura-cli/src/campaign_run.rs
@@ -264,7 +264,10 @@ pub(crate) fn run_campaign(target: &str, env: &Env) -> Result<(), String> {
 
     // Target resolution: a readable file is register-then-run sugar; a bare
     // 64-hex token addresses the store directly; anything else refuses naming
-    // both readings.
+    // both readings. A CLI arg is ephemeral input, so a leading `content:`
+    // display prefix is tolerated here (#194) — doc ref FIELDS stay bare-only
+    // (canonical-form byte stability).
+    let target = target.strip_prefix("content:").filter(|t| is_content_id(t)).unwrap_or(target);
     let campaign_id = if Path::new(target).is_file() {
         let doc = parse_valid_campaign(&PathBuf::from(target))?;
         registry
diff --git a/crates/aura-cli/src/graph_construct.rs b/crates/aura-cli/src/graph_construct.rs
index c9e585d..186c2e1 100644
--- a/crates/aura-cli/src/graph_construct.rs
+++ b/crates/aura-cli/src/graph_construct.rs
@@ -347,6 +347,12 @@ fn composite_from_any(text: &str, env: &crate::project::Env) -> Result<Composite
 /// `campaign run`'s target resolution uses, so the two FILE-or-id surfaces
 /// cannot drift apart on what counts as a store address.
 fn resolve_blueprint_text(target: &str, env: &crate::project::Env) -> Result<String, String> {
+    // A CLI arg tolerates the `content:` display prefix (#194); doc ref
+    // fields stay bare-only.
+    let target = target
+        .strip_prefix("content:")
+        .filter(|t| crate::campaign_run::is_content_id(t))
+        .unwrap_or(target);
     let path = Path::new(target);
     if path.is_file() {
         return std::fs::read_to_string(path)
@@ -405,7 +411,7 @@ fn register_blueprint(file: &Path, env: &crate::project::Env) -> Result<String,
     let registry = env.registry();
     registry.put_blueprint(&id, &canonical).map_err(|e| e.to_string())?;
     Ok(format!(
-        "registered blueprint content:{id} ({})",
+        "registered blueprint {id} ({})",
         registry.blueprint_path(&id).display()
     ))
 }
diff --git a/crates/aura-cli/src/research_docs.rs b/crates/aura-cli/src/research_docs.rs
index 2e30feb..79aacf6 100644
--- a/crates/aura-cli/src/research_docs.rs
+++ b/crates/aura-cli/src/research_docs.rs
@@ -179,7 +179,7 @@ fn register_process(file: &PathBuf, env: &Env) -> Result<(), String> {
     let registry = env.registry();
     let id = registry.put_process(&canonical).map_err(|e| e.to_string())?;
     println!(
-        "registered process content:{id} ({})",
+        "registered process {id} ({})",
         registry.process_path(&id).display()
     );
     Ok(())
@@ -205,7 +205,7 @@ fn introspect_process(cmd: &DocIntrospectCmd) -> Result<(), String> {
     if let Some(file) = &cmd.content_id {
         let doc = parse_valid_process(file)
             .map_err(|m| format!("an invalid document has no canonical form — {m}"))?;
-        println!("content:{}", aura_research::content_id_of(&process_to_json(&doc)));
+        println!("{}", aura_research::content_id_of(&process_to_json(&doc)));
         return Ok(());
     }
     unreachable!("guard_one_mode enforces one mode")
@@ -249,10 +249,25 @@ pub enum CampaignSub {
     Run { target: String },
 }
 
+/// The one authoring trap the referential tier can name outright: a ref that
+/// carries the `content:` DISPLAY prefix (doc ref fields are bare-only —
+/// canonical-form byte stability, #194).
+fn prefix_hint(id: &str) -> &'static str {
+    if id.starts_with("content:") {
+        " (refs use the bare 64-hex id — drop the 'content:' prefix)"
+    } else {
+        ""
+    }
+}
+
 pub(crate) fn ref_fault_prose(f: &RefFault) -> String {
     match f {
-        RefFault::ProcessNotFound(id) => format!("process {id} not found in the project store"),
-        RefFault::StrategyNotFound(id) => format!("strategy {id} not found in the blueprint store"),
+        RefFault::ProcessNotFound(id) => {
+            format!("process {id} not found in the project store{}", prefix_hint(id))
+        }
+        RefFault::StrategyNotFound(id) => {
+            format!("strategy {id} not found in the blueprint store{}", prefix_hint(id))
+        }
         RefFault::IdentityUnmatched(id) => format!("identity id {id} matches no stored blueprint"),
         RefFault::StrategyUnloadable { id, error } => {
             format!("strategy {id} cannot be loaded: {error}")
@@ -343,7 +358,7 @@ fn register_campaign(file: &PathBuf, env: &Env) -> Result<(), String> {
     let registry = env.registry();
     let id = registry.put_campaign(&canonical).map_err(|e| e.to_string())?;
     println!(
-        "registered campaign content:{id} ({})",
+        "registered campaign {id} ({})",
         registry.campaign_path(&id).display()
     );
     Ok(())
@@ -369,7 +384,7 @@ fn introspect_campaign(cmd: &DocIntrospectCmd) -> Result<(), String> {
     if let Some(file) = &cmd.content_id {
         let doc = parse_valid_campaign(file)
             .map_err(|m| format!("an invalid document has no canonical form — {m}"))?;
-        println!("content:{}", aura_research::content_id_of(&campaign_to_json(&doc)));
+        println!("{}", aura_research::content_id_of(&campaign_to_json(&doc)));
         return Ok(());
     }
     unreachable!("guard_one_mode enforces one mode")
@@ -412,6 +427,22 @@ mod tests {
         }
     }
 
+    #[test]
+    /// #194 (the prefix trap): a doc ref that carries the display `content:`
+    /// prefix (a copy-paste from register/introspect output) is bare-only in
+    /// canonical documents — the referential refusal names the prefix as the
+    /// cause instead of failing mute. A bare id keeps the plain refusal, so the
+    /// hint is conditional, not always-on.
+    fn ref_fault_prose_hints_when_a_ref_carries_the_content_prefix() {
+        let hash = "a".repeat(64);
+        let proc = ref_fault_prose(&RefFault::ProcessNotFound(format!("content:{hash}")));
+        let strat = ref_fault_prose(&RefFault::StrategyNotFound(format!("content:{hash}")));
+        assert!(proc.contains("drop the 'content:' prefix"), "process ref hint missing: {proc}");
+        assert!(strat.contains("drop the 'content:' prefix"), "strategy ref hint missing: {strat}");
+        let bare = ref_fault_prose(&RefFault::ProcessNotFound(hash));
+        assert!(!bare.contains("drop the 'content:' prefix"), "bare id must not carry the hint: {bare}");
+    }
+
     #[test]
     fn zero_walk_forward_length_prose_is_path_addressed_and_debug_free() {
         let prose = doc_fault_prose(&DocFault::ZeroWalkForwardLength { stage: 2, field: "step_ms" });
diff --git a/crates/aura-cli/tests/graph_construct.rs b/crates/aura-cli/tests/graph_construct.rs
index 001217a..69b2211 100644
--- a/crates/aura-cli/tests/graph_construct.rs
+++ b/crates/aura-cli/tests/graph_construct.rs
@@ -407,16 +407,19 @@ fn fixture(name: &str) -> String {
     format!("{}/tests/fixtures/{name}", env!("CARGO_MANIFEST_DIR"))
 }
 
-/// The id extracted from a `registered blueprint content:{id} ({path})` line.
+/// The id extracted from a `registered blueprint {id} ({path})` line.
+/// Prefix-tolerant across the #194 convention change (the display form dropped
+/// the glued `content:` prefix): the id is bare either way.
 fn registered_id(stdout: &str) -> String {
     stdout
         .lines()
-        .find(|l| l.starts_with("registered blueprint content:"))
+        .find(|l| l.starts_with("registered blueprint "))
         .expect("register line")
-        .trim_start_matches("registered blueprint content:")
+        .trim_start_matches("registered blueprint ")
         .split(' ')
         .next()
         .expect("id")
+        .trim_start_matches("content:")
         .to_string()
 }
 
@@ -428,6 +431,8 @@ fn graph_register_stores_and_prints_content_id() {
     let dir = temp_cwd("register");
     let (stdout, stderr, code) = run_in(&dir, &["graph", "register", &fixture("sma_signal.json")]);
     assert_eq!(code, Some(0), "stdout: {stdout} stderr: {stderr}");
+    // #194: the register verb prints the bare id — `registered blueprint <id> (<path>)`.
+    assert!(!stdout.contains("content:"), "register prints the bare id, no content: prefix: {stdout}");
     let id = registered_id(&stdout);
     assert_eq!(id.len(), 64, "a 64-hex content id: {id:?}");
     assert!(id.chars().all(|c| c.is_ascii_hexdigit()), "hex only: {id:?}");
@@ -514,6 +519,23 @@ fn graph_params_by_content_id_matches_params_by_file() {
     assert_eq!(by_id_out, "fast.length:I64\nslow.length:I64\n", "the raw open params, in order");
 }
 
+/// #194 (the prefix trap): a `--params <ID>` target may carry the display
+/// `content:` prefix copied verbatim from register/introspect output — the CLI
+/// strips it and resolves the bare store address, printing exactly the same raw
+/// axis namespace the bare id (and the file) print.
+#[test]
+fn graph_params_tolerates_content_prefix_on_target() {
+    let dir = temp_cwd("params-content-prefix");
+    let bp = fixture("sma_signal_open.json");
+    let (reg_out, reg_err, reg_code) = run_in(&dir, &["graph", "register", &bp]);
+    assert_eq!(reg_code, Some(0), "register: {reg_out} {reg_err}");
+    let id = registered_id(&reg_out);
+    let (pfx_out, pfx_err, pfx_code) =
+        run_in(&dir, &["graph", "introspect", "--params", &format!("content:{id}")]);
+    assert_eq!(pfx_code, Some(0), "content:-prefixed --params must resolve: stdout {pfx_out} stderr {pfx_err}");
+    assert_eq!(pfx_out, "fast.length:I64\nslow.length:I64\n", "same raw axis namespace as the bare id");
+}
+
 /// Property (#196, negative): `--params <ID>` with a well-shaped 64-hex id
 /// that was never registered refuses with a store-miss message, not a panic
 /// or a silent empty namespace — the registry lookup branch of
diff --git a/crates/aura-cli/tests/research_docs.rs b/crates/aura-cli/tests/research_docs.rs
index d6be012..9890c87 100644
--- a/crates/aura-cli/tests/research_docs.rs
+++ b/crates/aura-cli/tests/research_docs.rs
@@ -152,8 +152,12 @@ fn process_introspect_vocabulary_block_and_content_id() {
     write_doc(&dir, "p.process.json", PROCESS_DOC);
     let (out, code) = run_code_in(&dir, &["process", "introspect", "--content-id", "p.process.json"]);
     assert_eq!(code, Some(0), "stdout/stderr: {out}");
-    let line = out.lines().find(|l| l.starts_with("content:")).expect("id line");
-    assert_eq!(line.len(), "content:".len() + 64);
+    // #194: --content-id prints the bare 64-hex id (matching `graph introspect
+    // --content-id` and the store filename), no glued `content:` display prefix.
+    let line = out.lines().last().expect("id line").trim();
+    assert_eq!(line.len(), 64, "bare 64-hex id, no content: prefix: {out}");
+    assert!(line.chars().all(|c| c.is_ascii_hexdigit()), "bare hex id: {out}");
+    assert!(!out.contains("content:"), "--content-id must not glue the content: prefix: {out}");
 }
 
 #[test]
@@ -187,9 +191,11 @@ fn process_register_stores_content_addressed_under_runs_root() {
     write_doc(&dir, "p.process.json", PROCESS_DOC);
     let (out, code) = run_code_in(&dir, &["process", "register", "p.process.json"]);
     assert_eq!(code, Some(0), "stdout/stderr: {out}");
-    let line = out.lines().find(|l| l.starts_with("registered process content:")).expect("line");
+    // #194: the register verb prints the bare id — `registered process <id> (<path>)`.
+    let line = out.lines().find(|l| l.starts_with("registered process ")).expect("line");
+    assert!(!line.contains("content:"), "register line prints the bare id, no content: prefix: {line}");
     let id = line
-        .trim_start_matches("registered process content:")
+        .trim_start_matches("registered process ")
         .split(' ')
         .next()
         .expect("id");
@@ -308,12 +314,13 @@ fn campaign_validate_in_project_reports_referential_tier_end_to_end() {
     assert_eq!(proc_code, Some(0), "seed process register failed: {proc_out}");
     let proc_id = proc_out
         .lines()
-        .find(|l| l.starts_with("registered process content:"))
+        .find(|l| l.starts_with("registered process "))
         .expect("register line")
-        .trim_start_matches("registered process content:")
+        .trim_start_matches("registered process ")
         .split(' ')
         .next()
         .expect("id")
+        .trim_start_matches("content:")
         .to_string();
 
     // "fast.length": the axis name is the RAW composite's `param_space` name.
@@ -424,8 +431,11 @@ fn campaign_introspect_content_id_prints_hash() {
     write_doc(&dir, "c.campaign.json", CAMPAIGN_DOC);
     let (out, code) = run_code_in(&dir, &["campaign", "introspect", "--content-id", "c.campaign.json"]);
     assert_eq!(code, Some(0), "stdout/stderr: {out}");
-    let line = out.lines().find(|l| l.starts_with("content:")).expect("id line");
-    assert_eq!(line.len(), "content:".len() + 64);
+    // #194: --content-id prints the bare 64-hex id, no glued `content:` prefix.
+    let line = out.lines().last().expect("id line").trim();
+    assert_eq!(line.len(), 64, "bare 64-hex id, no content: prefix: {out}");
+    assert!(line.chars().all(|c| c.is_ascii_hexdigit()), "bare hex id: {out}");
+    assert!(!out.contains("content:"), "--content-id must not glue the content: prefix: {out}");
 }
 
 #[test]
@@ -434,9 +444,11 @@ fn campaign_register_stores_content_addressed_under_runs_root() {
     write_doc(&dir, "c.campaign.json", CAMPAIGN_DOC);
     let (out, code) = run_code_in(&dir, &["campaign", "register", "c.campaign.json"]);
     assert_eq!(code, Some(0), "stdout/stderr: {out}");
-    let line = out.lines().find(|l| l.starts_with("registered campaign content:")).expect("line");
+    // #194: the register verb prints the bare id — `registered campaign <id> (<path>)`.
+    let line = out.lines().find(|l| l.starts_with("registered campaign ")).expect("line");
+    assert!(!line.contains("content:"), "register line prints the bare id, no content: prefix: {line}");
     let id = line
-        .trim_start_matches("registered campaign content:")
+        .trim_start_matches("registered campaign ")
         .split(' ')
         .next()
         .expect("id");
@@ -527,12 +539,13 @@ fn register_process_doc(dir: &Path, file: &str, doc: &str) -> String {
     let (out, code) = run_code_in(dir, &["process", "register", file]);
     assert_eq!(code, Some(0), "process register failed: {out}");
     out.lines()
-        .find(|l| l.starts_with("registered process content:"))
+        .find(|l| l.starts_with("registered process "))
         .expect("register line")
-        .trim_start_matches("registered process content:")
+        .trim_start_matches("registered process ")
         .split(' ')
         .next()
         .expect("id")
+        .trim_start_matches("content:")
         .to_string()
 }
 
@@ -821,12 +834,13 @@ fn campaign_run_by_content_id_matches_file_sugar_refusal() {
     assert_eq!(reg_code, Some(0), "register failed: {reg_out}");
     let id = reg_out
         .lines()
-        .find(|l| l.starts_with("registered campaign content:"))
+        .find(|l| l.starts_with("registered campaign "))
         .expect("register line")
-        .trim_start_matches("registered campaign content:")
+        .trim_start_matches("registered campaign ")
         .split(' ')
         .next()
         .expect("id")
+        .trim_start_matches("content:")
         .to_string();
     let (id_out, id_code) = run_code_in(dir, &["campaign", "run", &id]);
     assert_eq!(id_code, Some(1), "stdout/stderr: {id_out}");
@@ -836,6 +850,53 @@ fn campaign_run_by_content_id_matches_file_sugar_refusal() {
     assert_eq!(file_line, id_line, "file- and id-addressed runs must refuse identically");
 }
 
+/// #194 (the prefix trap): a `campaign run` target may carry the display
+/// `content:` prefix copied verbatim from the tool's own register/introspect
+/// output — the CLI strips it and resolves the bare store address. Pinned
+/// observably: running the SAME registered campaign by bare id and by its
+/// `content:`-prefixed form must refuse identically (proof the prefix is
+/// stripped, not read as a second, unresolvable address). Both refuse at the
+/// data-free v1 preflight (MC process), so no real data is needed.
+#[test]
+fn campaign_run_tolerates_content_prefix_on_target() {
+    let _fixture = project_lock();
+    let dir = built_project();
+    let runs_dir = dir.join("runs");
+    std::fs::remove_dir_all(&runs_dir).ok();
+    let _cleanup = ScratchGuard(vec![
+        ScratchPath::Dir(runs_dir.clone()),
+        ScratchPath::File(dir.join("prefix.process.json")),
+        ScratchPath::File(dir.join("prefix.campaign.json")),
+    ]);
+    let bp_id = seed_blueprint(dir, "campaign-run-prefix-seed");
+    let proc_id = register_process_doc(dir, "prefix.process.json", MC_PROCESS_DOC);
+    write_doc(dir, "prefix.campaign.json", &campaign_doc_json(&bp_id, &proc_id, (1, 2), "", ""));
+
+    let (reg_out, reg_code) = run_code_in(dir, &["campaign", "register", "prefix.campaign.json"]);
+    assert_eq!(reg_code, Some(0), "register failed: {reg_out}");
+    let id = reg_out
+        .lines()
+        .find(|l| l.starts_with("registered campaign "))
+        .expect("register line")
+        .trim_start_matches("registered campaign ")
+        .split(' ')
+        .next()
+        .expect("id")
+        .trim_start_matches("content:")
+        .to_string();
+
+    let (bare_out, _) = run_code_in(dir, &["campaign", "run", &id]);
+    let (pfx_out, _) = run_code_in(dir, &["campaign", "run", &format!("content:{id}")]);
+
+    let pfx_line = pfx_out.lines().find(|l| l.starts_with("aura: ")).expect("prefixed refusal line");
+    assert!(
+        !pfx_line.contains("neither a readable .json file nor a 64-hex content id"),
+        "a content:-prefixed target must resolve as the bare id, not refuse as an unknown target: {pfx_line}"
+    );
+    let bare_line = bare_out.lines().find(|l| l.starts_with("aura: ")).expect("bare refusal line");
+    assert_eq!(bare_line, pfx_line, "bare-id and content:-prefixed runs must resolve identically");
+}
+
 /// Property (#196 on-ramp x #198 executor): a blueprint registered through
 /// `aura graph register` — NOT the pre-#196 `aura sweep` side-effect
 /// `seed_blueprint` relies on elsewhere in this file — is a fully valid
@@ -863,12 +924,13 @@ fn campaign_run_accepts_a_graph_register_seeded_strategy() {
     assert_eq!(reg_code, Some(0), "graph register failed: {reg_out}");
     let bp_id = reg_out
         .lines()
-        .find(|l| l.starts_with("registered blueprint content:"))
+        .find(|l| l.starts_with("registered blueprint "))
         .expect("register line")
-        .trim_start_matches("registered blueprint content:")
+        .trim_start_matches("registered blueprint ")
         .split(' ')
         .next()
         .expect("id")
+        .trim_start_matches("content:")
         .to_string();
 
     let proc_id = register_process_doc(dir, "onramp.process.json", SWEEP_ONLY_PROCESS_DOC);