diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 1a583cf7813..0f8cfd7f538 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -1250,8 +1250,8 @@ supported_targets! {
 
     ("mips64-openwrt-linux-musl", mips64_openwrt_linux_musl),
 
-    ("aarch64-unknown-nto-qnx7.1.0", aarch64_unknown_nto_qnx_710),
-    ("x86_64-pc-nto-qnx7.1.0", x86_64_pc_nto_qnx710),
+    ("aarch64-unknown-nto-qnx710", aarch64_unknown_nto_qnx_710),
+    ("x86_64-pc-nto-qnx710", x86_64_pc_nto_qnx710),
 }
 
 /// Cow-Vec-Str: Cow<'static, [Cow<'static, str>]>
diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index 27e911c6be5..d0c3ddf2606 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -214,7 +214,7 @@ target | std | host | notes
 [`aarch64-kmc-solid_asp3`](platform-support/kmc-solid.md) | ✓ |  | ARM64 SOLID with TOPPERS/ASP3
 [`aarch64-nintendo-switch-freestanding`](platform-support/aarch64-nintendo-switch-freestanding.md) | * |  | ARM64 Nintendo Switch, Horizon
 [`aarch64-pc-windows-gnullvm`](platform-support/pc-windows-gnullvm.md) | ✓ | ✓ |
-[`aarch64-unknown-nto-qnx7.1.0`](platform-support/nto-qnx.md) | ? |  | ARM64 QNX Neutrino 7.1 RTOS |
+[`aarch64-unknown-nto-qnx710`](platform-support/nto-qnx.md) | ? |  | ARM64 QNX Neutrino 7.1 RTOS |
 `aarch64-unknown-freebsd` | ✓ | ✓ | ARM64 FreeBSD
 `aarch64-unknown-hermit` | ✓ |  | ARM64 HermitCore
 `aarch64-unknown-linux-gnu_ilp32` | ✓ | ✓ | ARM64 Linux (ILP32 ABI)
@@ -305,7 +305,7 @@ target | std | host | notes
 `x86_64-apple-ios-macabi` | ✓ |  | Apple Catalyst on x86_64
 `x86_64-apple-tvos` | * | | x86 64-bit tvOS
 [`x86_64-apple-watchos-sim`](platform-support/apple-watchos.md) | ✓ | | x86 64-bit Apple WatchOS simulator
-[`x86_64-pc-nto-qnx7.1.0`](platform-support/nto-qnx.md) | ? |  | x86 64-bit QNX Neutrino 7.1 RTOS |
+[`x86_64-pc-nto-qnx710`](platform-support/nto-qnx.md) | ? |  | x86 64-bit QNX Neutrino 7.1 RTOS |
 [`x86_64-pc-windows-gnullvm`](platform-support/pc-windows-gnullvm.md) | ✓ | ✓ |
 `x86_64-pc-windows-msvc` | * |  | 64-bit Windows XP support
 `x86_64-sun-solaris` | ? |  | Deprecated target for 64-bit Solaris 10/11, illumos
diff --git a/src/doc/rustc/src/platform-support/nto-qnx.md b/src/doc/rustc/src/platform-support/nto-qnx.md
index 2f6ea94d113..37d0c31976c 100644
--- a/src/doc/rustc/src/platform-support/nto-qnx.md
+++ b/src/doc/rustc/src/platform-support/nto-qnx.md
@@ -93,15 +93,15 @@ Run the following:
 
 ```bash
 env \
-    CC_aarch64-unknown-nto-qnx7.1.0="qcc" \
-    CFLAGS_aarch64-unknown-nto-qnx7.1.0="-Vgcc_ntoaarch64le_cxx" \
-    CXX_aarch64-unknown-nto-qnx7.1.0="qcc" \
-    AR_aarch64_unknown_nto_qnx7.1.0="ntoaarch64-ar" \
-    CC_x86_64-pc-nto-qnx7.1.0="qcc" \
-    CFLAGS_x86_64-pc-nto-qnx7.1.0="-Vgcc_ntox86_64_cxx" \
-    CXX_x86_64-pc-nto-qnx7.1.0="qcc" \
-    AR_x86_64_pc_nto_qnx7.1.0="ntox86_64-ar" \
-        ./x.py build --target aarch64-unknown-nto-qnx7.1.0 --target x86_64-pc-nto-qnx7.1.0 --target x86_64-unknown-linux-gnu rustc library/core library/alloc/
+    CC_aarch64-unknown-nto-qnx710="qcc" \
+    CFLAGS_aarch64-unknown-nto-qnx710="-Vgcc_ntoaarch64le_cxx" \
+    CXX_aarch64-unknown-nto-qnx710="qcc" \
+    AR_aarch64_unknown_nto_qnx710="ntoaarch64-ar" \
+    CC_x86_64-pc-nto-qnx710="qcc" \
+    CFLAGS_x86_64-pc-nto-qnx710="-Vgcc_ntox86_64_cxx" \
+    CXX_x86_64-pc-nto-qnx710="qcc" \
+    AR_x86_64_pc_nto_qnx710="ntox86_64-ar" \
+        ./x.py build --target aarch64-unknown-nto-qnx710 --target x86_64-pc-nto-qnx710 --target x86_64-unknown-linux-gnu rustc library/core library/alloc/
 ```
 
 ## Building Rust programs
diff --git a/src/doc/rustc/src/target-tier-policy.md b/src/doc/rustc/src/target-tier-policy.md
index df9131ce84a..95932db14e1 100644
--- a/src/doc/rustc/src/target-tier-policy.md
+++ b/src/doc/rustc/src/target-tier-policy.md
@@ -158,6 +158,8 @@ approved by the appropriate team for that shared code before acceptance.
     the name of the target makes people extremely likely to form incorrect
     beliefs about what it targets, the name should be changed or augmented to
     disambiguate it.
+  - If possible, use only letters, numbers, dashes and underscores for the name.
+    Periods (`.`) are known to cause issues in Cargo.
 - Tier 3 targets may have unusual requirements to build or use, but must not
   create legal issues or impose onerous legal terms for the Rust project or for
   Rust developers or users.
diff --git a/src/tools/tier-check/src/main.rs b/src/tools/tier-check/src/main.rs
index a41e2d6e3aa..c74d37c61e8 100644
--- a/src/tools/tier-check/src/main.rs
+++ b/src/tools/tier-check/src/main.rs
@@ -44,7 +44,23 @@ fn main() {
             target, filename, src
         );
     }
-    if !missing.is_empty() || !extra.is_empty() {
+    // Check target names for unwanted characters like `.` that can cause problems e.g. in Cargo.
+    // See also Tier 3 target policy.
+    // If desired, target names can ignore this check.
+    let ignore_target_names =
+        vec!["thumbv8m.base-none-eabi", "thumbv8m.main-none-eabi", "thumbv8m.main-none-eabihf"];
+    let mut invalid_target_name_found = false;
+    for target in &target_list {
+        if !ignore_target_names.contains(target)
+            && !target.chars().all(|c| c.is_ascii_alphanumeric() || c == '-' || c == '_')
+        {
+            invalid_target_name_found = true;
+            eprintln!(
+                "error: Target name `{target}` contains other characters than ASCII alphanumeric (a-z, A-Z, 0-9), dash (-) or underscore (_)."
+            );
+        }
+    }
+    if !missing.is_empty() || !extra.is_empty() || invalid_target_name_found {
         std::process::exit(1);
     }
 }