use consistent title capitalization

19 files changed, 44 insertions, 45 deletions

diff --git a/src/doc/rustc-dev-guide/src/SUMMARY.md b/src/doc/rustc-dev-guide/src/SUMMARY.md
index 95a3cd7c790..05c43c83a9d 100644
--- a/src/doc/rustc-dev-guide/src/SUMMARY.md
+++ b/src/doc/rustc-dev-guide/src/SUMMARY.md
@@ -10,9 +10,9 @@
 - [How to build and run the compiler](./building/how-to-build-and-run.md)
     - [Quickstart](./building/quickstart.md)
     - [Prerequisites](./building/prerequisites.md)
-    - [Suggested Workflows](./building/suggested.md)
+    - [Suggested workflows](./building/suggested.md)
     - [Distribution artifacts](./building/build-install-distribution-artifacts.md)
-    - [Building Documentation](./building/compiler-documenting.md)
+    - [Building documentation](./building/compiler-documenting.md)
     - [Rustdoc overview](./rustdoc.md)
     - [Adding a new target](./building/new-target.md)
     - [Optimized build](./building/optimized-build.md)
@@ -42,11 +42,11 @@
     - [with the linux perf tool](./profiling/with_perf.md)
     - [with Windows Performance Analyzer](./profiling/wpa_profiling.md)
     - [with the Rust benchmark suite](./profiling/with_rustc_perf.md)
-- [crates.io Dependencies](./crates-io.md)
+- [crates.io dependencies](./crates-io.md)
 
 # Contributing to Rust
 
-- [Contribution Procedures](./contributing.md)
+- [Contribution procedures](./contributing.md)
 - [About the compiler team](./compiler-team.md)
 - [Using Git](./git.md)
 - [Mastering @rustbot](./rustbot.md)
@@ -56,7 +56,7 @@
 - [Stabilizing Features](./stabilization_guide.md)
 - [Feature Gates](./feature-gates.md)
 - [Coding conventions](./conventions.md)
-- [Procedures for Breaking Changes](./bug-fix-procedure.md)
+- [Procedures for breaking changes](./bug-fix-procedure.md)
 - [Using external repositories](./external-repos.md)
 - [Fuzzing](./fuzzing.md)
 - [Notification groups](notification-groups/about.md)
@@ -88,14 +88,14 @@
 - [Overview of the compiler](./overview.md)
 - [The compiler source code](./compiler-src.md)
 - [Queries: demand-driven compilation](./query.md)
-    - [The Query Evaluation Model in Detail](./queries/query-evaluation-model-in-detail.md)
+    - [The Query Evaluation Model in detail](./queries/query-evaluation-model-in-detail.md)
     - [Incremental compilation](./queries/incremental-compilation.md)
-    - [Incremental compilation In Detail](./queries/incremental-compilation-in-detail.md)
-    - [Debugging and Testing](./incrcomp-debugging.md)
+    - [Incremental compilation in detail](./queries/incremental-compilation-in-detail.md)
+    - [Debugging and testing](./incrcomp-debugging.md)
     - [Salsa](./queries/salsa.md)
-- [Memory Management in Rustc](./memory.md)
-- [Serialization in Rustc](./serialization.md)
-- [Parallel Compilation](./parallel-rustc.md)
+- [Memory management in rustc](./memory.md)
+- [Serialization in rustc](./serialization.md)
+- [Parallel compilation](./parallel-rustc.md)
 - [Rustdoc internals](./rustdoc-internals.md)
     - [Search](./rustdoc-internals/search.md)
 	- [The `rustdoc` test suite](./rustdoc-internals/rustdoc-test-suite.md)
@@ -103,14 +103,14 @@
 
 - [Prologue](./part-3-intro.md)
 - [Syntax and the AST](./syntax-intro.md)
-    - [Lexing and Parsing](./the-parser.md)
+    - [Lexing and parsing](./the-parser.md)
     - [Macro expansion](./macro-expansion.md)
     - [Name resolution](./name-resolution.md)
     - [Attributes](./attributes.md)
-    - [`#[test]` Implementation](./test-implementation.md)
-    - [Panic Implementation](./panic-implementation.md)
-    - [AST Validation](./ast-validation.md)
-    - [Feature Gate Checking](./feature-gate-ck.md)
+    - [`#[test]` implementation](./test-implementation.md)
+    - [Panic implementation](./panic-implementation.md)
+    - [AST validation](./ast-validation.md)
+    - [Feature gate checking](./feature-gate-ck.md)
     - [Lang Items](./lang-items.md)
 - [The HIR (High-level IR)](./hir.md)
     - [Lowering AST to HIR](./ast-lowering.md)
@@ -129,7 +129,7 @@
     - [Example: Type checking](./rustc-driver/interacting-with-the-ast.md)
     - [Example: Getting diagnostics](./rustc-driver/getting-diagnostics.md)
     - [Remarks on perma-unstable features](./rustc-driver/remarks-on-perma-unstable-features.md)
-- [Errors and Lints](diagnostics.md)
+- [Errors and lints](diagnostics.md)
     - [Diagnostic and subdiagnostic structs](./diagnostics/diagnostic-structs.md)
     - [Translation](./diagnostics/translation.md)
     - [`LintStore`](./diagnostics/lintstore.md)
@@ -175,14 +175,14 @@
 - [Type checking](./type-checking.md)
     - [Method Lookup](./method-lookup.md)
     - [Variance](./variance.md)
-    - [Coherence Checking](./coherence.md)
-    - [Opaque Types](./opaque-types-type-alias-impl-trait.md)
+    - [Coherence checking](./coherence.md)
+    - [Opaque types](./opaque-types-type-alias-impl-trait.md)
         - [Inference details](./opaque-types-impl-trait-inference.md)
         - [Return Position Impl Trait In Trait](./return-position-impl-trait-in-trait.md)
         - [Region inference restrictions][opaque-infer]
 - [Const condition checking](./effects.md)
 - [Pattern and Exhaustiveness Checking](./pat-exhaustive-checking.md)
-- [Unsafety Checking](./unsafety-checking.md)
+- [Unsafety checking](./unsafety-checking.md)
 - [MIR dataflow](./mir/dataflow.md)
 - [Drop elaboration](./mir/drop-elaboration.md)
 - [The borrow checker](./borrow_check.md)
diff --git a/src/doc/rustc-dev-guide/src/ast-validation.md b/src/doc/rustc-dev-guide/src/ast-validation.md
index fa0f1d954f8..8f10bbecf21 100644
--- a/src/doc/rustc-dev-guide/src/ast-validation.md
+++ b/src/doc/rustc-dev-guide/src/ast-validation.md
@@ -1,4 +1,4 @@
-# AST Validation
+# AST validation
 
 _AST validation_ is a separate AST pass that visits each
 item in the tree and performs simple checks. This pass
diff --git a/src/doc/rustc-dev-guide/src/bug-fix-procedure.md b/src/doc/rustc-dev-guide/src/bug-fix-procedure.md
index e6a16df6d2a..8e6725c54ef 100644
--- a/src/doc/rustc-dev-guide/src/bug-fix-procedure.md
+++ b/src/doc/rustc-dev-guide/src/bug-fix-procedure.md
@@ -1,4 +1,4 @@
-# Procedures for Breaking Changes
+# Procedures for breaking changes
 
 <!-- toc -->
 
diff --git a/src/doc/rustc-dev-guide/src/building/suggested.md b/src/doc/rustc-dev-guide/src/building/suggested.md
index 43ff2ba726f..a70d9d88ec3 100644
--- a/src/doc/rustc-dev-guide/src/building/suggested.md
+++ b/src/doc/rustc-dev-guide/src/building/suggested.md
@@ -1,4 +1,4 @@
-# Suggested Workflows
+# Suggested workflows
 
 The full bootstrapping process takes quite a while. Here are some suggestions to
 make your life easier.
diff --git a/src/doc/rustc-dev-guide/src/coherence.md b/src/doc/rustc-dev-guide/src/coherence.md
index b3af101fb87..73f9213bf40 100644
--- a/src/doc/rustc-dev-guide/src/coherence.md
+++ b/src/doc/rustc-dev-guide/src/coherence.md
@@ -1,4 +1,3 @@
-
 # Coherence
 
 > NOTE: this is based on [notes by @lcnr](https://github.com/rust-lang/rust/pull/121848)
diff --git a/src/doc/rustc-dev-guide/src/contributing.md b/src/doc/rustc-dev-guide/src/contributing.md
index 0e622fff8df..cc68c011d61 100644
--- a/src/doc/rustc-dev-guide/src/contributing.md
+++ b/src/doc/rustc-dev-guide/src/contributing.md
@@ -1,4 +1,4 @@
-# Contribution Procedures
+# Contribution procedures
 
 <!-- toc -->
 
diff --git a/src/doc/rustc-dev-guide/src/crates-io.md b/src/doc/rustc-dev-guide/src/crates-io.md
index 403d61a81da..4431585a2f0 100644
--- a/src/doc/rustc-dev-guide/src/crates-io.md
+++ b/src/doc/rustc-dev-guide/src/crates-io.md
@@ -1,4 +1,4 @@
-# crates.io Dependencies
+# crates.io dependencies
 
 The Rust compiler supports building with some dependencies from `crates.io`.
 Examples are `log` and `env_logger`.
diff --git a/src/doc/rustc-dev-guide/src/diagnostics.md b/src/doc/rustc-dev-guide/src/diagnostics.md
index 6f72ea902f5..2f8f4b0ab8a 100644
--- a/src/doc/rustc-dev-guide/src/diagnostics.md
+++ b/src/doc/rustc-dev-guide/src/diagnostics.md
@@ -1,4 +1,4 @@
-# Errors and Lints
+# Errors and lints
 
 <!-- toc -->
 
@@ -772,7 +772,7 @@ store.register_renamed("single_use_lifetime", "single_use_lifetimes");
 [`store.register_removed`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/struct.LintStore.html#method.register_removed
 [`rustc_lint::register_builtins`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/fn.register_builtins.html
 
-### Lint Groups
+### Lint groups
 
 Lints can be turned on in groups. These groups are declared in the
 [`register_builtins`][rbuiltins] function in [`rustc_lint::lib`][builtin]. The
diff --git a/src/doc/rustc-dev-guide/src/feature-gates.md b/src/doc/rustc-dev-guide/src/feature-gates.md
index 24ce9bb71bf..9806f73c483 100644
--- a/src/doc/rustc-dev-guide/src/feature-gates.md
+++ b/src/doc/rustc-dev-guide/src/feature-gates.md
@@ -1,4 +1,4 @@
-# Feature Gates
+# Feature gates
 
 This chapter is intended to provide basic help for adding, removing, and
 modifying feature gates.
diff --git a/src/doc/rustc-dev-guide/src/incrcomp-debugging.md b/src/doc/rustc-dev-guide/src/incrcomp-debugging.md
index 7045d3fa39d..a548215cf0c 100644
--- a/src/doc/rustc-dev-guide/src/incrcomp-debugging.md
+++ b/src/doc/rustc-dev-guide/src/incrcomp-debugging.md
@@ -1,4 +1,4 @@
-# Debugging and Testing Dependencies
+# Debugging and testing dependencies
 
 ## Testing the dependency graph
 
diff --git a/src/doc/rustc-dev-guide/src/memory.md b/src/doc/rustc-dev-guide/src/memory.md
index 1e030ff45a7..eeb4a813980 100644
--- a/src/doc/rustc-dev-guide/src/memory.md
+++ b/src/doc/rustc-dev-guide/src/memory.md
@@ -1,4 +1,4 @@
-# Memory Management in Rustc
+# Memory management in rustc
 
 Generally rustc tries to be pretty careful how it manages memory.
 The compiler allocates _a lot_ of data structures throughout compilation,
diff --git a/src/doc/rustc-dev-guide/src/panic-implementation.md b/src/doc/rustc-dev-guide/src/panic-implementation.md
index f3587428667..468190ffccd 100644
--- a/src/doc/rustc-dev-guide/src/panic-implementation.md
+++ b/src/doc/rustc-dev-guide/src/panic-implementation.md
@@ -1,4 +1,4 @@
-# Panicking in rust
+# Panicking in Rust
 
 <!-- toc -->
 
diff --git a/src/doc/rustc-dev-guide/src/parallel-rustc.md b/src/doc/rustc-dev-guide/src/parallel-rustc.md
index 690fb19c9f5..ce69b66c2da 100644
--- a/src/doc/rustc-dev-guide/src/parallel-rustc.md
+++ b/src/doc/rustc-dev-guide/src/parallel-rustc.md
@@ -1,4 +1,4 @@
-# Parallel Compilation
+# Parallel compilation
 
 <div class="warning">
 As of <!-- date-check --> November 2024,
@@ -28,7 +28,7 @@ The following sections are kept for now but are quite outdated.
 
 [codegen]: backend/codegen.md
 
-## Code Generation
+## Code generation
 
 During monomorphization the compiler splits up all the code to
 be generated into smaller chunks called _codegen units_. These are then generated by
@@ -38,7 +38,7 @@ occurs in the [`rustc_codegen_ssa::base`] module.
 
 [`rustc_codegen_ssa::base`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_codegen_ssa/base/index.html
 
-## Data Structures
+## Data structures
 
 The underlying thread-safe data-structures used in the parallel compiler
 can be found in the [`rustc_data_structures::sync`] module. These data structures 
@@ -83,7 +83,7 @@ can be accessed directly through `Deref::deref`.
 [`rustc_data_structures::sync::worker_local`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_data_structures/sync/worker_local/index.html
 [`WorkerLocal`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_data_structures/sync/worker_local/struct.WorkerLocal.html
 
-## Parallel Iterator
+## Parallel iterator
 
 The parallel iterators provided by the [`rayon`] crate are easy ways to
 implement parallelism. In the current implementation of the parallel compiler
@@ -124,7 +124,7 @@ the parallel iterator function has been used are as follows:
 
 There are still many loops that have the potential to use parallel iterators.
 
-## Query System
+## Query system
 
 The query model has some properties that make it actually feasible to evaluate
 multiple queries in parallel without too much effort:
diff --git a/src/doc/rustc-dev-guide/src/queries/incremental-compilation-in-detail.md b/src/doc/rustc-dev-guide/src/queries/incremental-compilation-in-detail.md
index 4133b196c0a..03c822d4fee 100644
--- a/src/doc/rustc-dev-guide/src/queries/incremental-compilation-in-detail.md
+++ b/src/doc/rustc-dev-guide/src/queries/incremental-compilation-in-detail.md
@@ -1,4 +1,4 @@
-# Incremental Compilation In Detail
+# Incremental Compilation in detail
 
 <!-- toc -->
 
diff --git a/src/doc/rustc-dev-guide/src/queries/query-evaluation-model-in-detail.md b/src/doc/rustc-dev-guide/src/queries/query-evaluation-model-in-detail.md
index f7f204bf79d..444e20bc580 100644
--- a/src/doc/rustc-dev-guide/src/queries/query-evaluation-model-in-detail.md
+++ b/src/doc/rustc-dev-guide/src/queries/query-evaluation-model-in-detail.md
@@ -1,4 +1,4 @@
-# The Query Evaluation Model in Detail
+# The Query Evaluation Model in detail
 
 <!-- toc -->
 
diff --git a/src/doc/rustc-dev-guide/src/serialization.md b/src/doc/rustc-dev-guide/src/serialization.md
index 0ff04990128..670a37ffb0a 100644
--- a/src/doc/rustc-dev-guide/src/serialization.md
+++ b/src/doc/rustc-dev-guide/src/serialization.md
@@ -1,4 +1,4 @@
-# Serialization in Rustc
+# Serialization in rustc
 
 rustc has to [serialize] and deserialize various data during compilation.
 Specifically:
diff --git a/src/doc/rustc-dev-guide/src/test-implementation.md b/src/doc/rustc-dev-guide/src/test-implementation.md
index bee783c0fa6..e906dd29f25 100644
--- a/src/doc/rustc-dev-guide/src/test-implementation.md
+++ b/src/doc/rustc-dev-guide/src/test-implementation.md
@@ -83,7 +83,7 @@ with your hand-written one, it will not share a [Symbol][Symbol]. This
 technique prevents name collision during code generation and is the foundation
 of Rust's [`macro`] hygiene.
 
-## Step 2: Harness Generation
+## Step 2: Harness generation
 
 Now that our tests are accessible from the root of our crate, we need to do
 something with them using [`rustc_ast`][ast] generates a module like so:
@@ -106,7 +106,7 @@ called [`test`][test] that is part of Rust core, that implements all of the
 runtime for testing. [`test`][test]'s interface is unstable, so the only stable way
 to interact with it is through the `#[test]` macro.
 
-## Step 3: Test Object Generation
+## Step 3: Test object generation
 
 If you've written tests in Rust before, you may be familiar with some of the
 optional attributes available on test functions. For example, a test can be
diff --git a/src/doc/rustc-dev-guide/src/the-parser.md b/src/doc/rustc-dev-guide/src/the-parser.md
index 60a71ae3873..601a81e2e48 100644
--- a/src/doc/rustc-dev-guide/src/the-parser.md
+++ b/src/doc/rustc-dev-guide/src/the-parser.md
@@ -1,4 +1,4 @@
-# Lexing and Parsing
+# Lexing and parsing
 
 The very first thing the compiler does is take the program (in UTF-8 Unicode text)
 and turn it into a data format the compiler can work with more conveniently than strings.
@@ -59,7 +59,7 @@ Note that while parsing, we may encounter macro definitions or invocations.
 We set these aside to be expanded (see [Macro Expansion](./macro-expansion.md)).
 Expansion itself may require parsing the output of a macro, which may reveal more macros to be expanded, and so on.
 
-## More on Lexical Analysis
+## More on lexical analysis
 
 Code for lexical analysis is split between two crates:
 
diff --git a/src/doc/rustc-dev-guide/src/unsafety-checking.md b/src/doc/rustc-dev-guide/src/unsafety-checking.md
index 1130878944d..fbc19d8961c 100644
--- a/src/doc/rustc-dev-guide/src/unsafety-checking.md
+++ b/src/doc/rustc-dev-guide/src/unsafety-checking.md
@@ -1,4 +1,4 @@
-# Unsafety Checking
+# Unsafety checking
 
 Certain expressions in Rust can violate memory safety and as such need to be
 inside an `unsafe` block or function. The compiler will also warn if an unsafe