diff --git a/features_c11.yaml b/features_c11.yaml
index 820b5f8..c78bb72 100644
--- a/features_c11.yaml
+++ b/features_c11.yaml
@@ -9,6 +9,7 @@ features:
       - MSVC 14.28
       - Xcode 16.1
       - TinyCC
+      - R++
   - desc: "Generic selection (`_Generic`)"
     paper: N1441
     content: c-generic.md
@@ -27,6 +28,7 @@ features:
       - Clang 3.1
       - MSVC 14.27
       - Xcode 16.1
+      - R++
   - desc: "Alignment support (`_Alignas`, `_Alignof`, `<stdalign.h>`)"
     paper: N1353
     content: c-alignas-alignof.md
@@ -54,6 +56,7 @@ features:
       - Clang 3.3
       - MSVC 14.37
       - Xcode 16.1
+      - R++
   - desc: "Multi-threading support (`<threads.h>`)"
     paper: N1437
     content: c-threads.md
@@ -72,6 +75,7 @@ features:
       - Xcode 16.1
       - owcc
       - TinyCC
+      - R++
   - desc: "Unicode support (`<uchar.h>`, `u/U` prefixes)"
     summary: "Unicode character types, literals, and conversion functions."
     paper: N1487
diff --git a/features_c23.yaml b/features_c23.yaml
index d779496..7842d94 100644
--- a/features_c23.yaml
+++ b/features_c23.yaml
@@ -176,6 +176,7 @@ features:
       - GCC 11
       - Clang 16
       - Xcode 16.1
+      - R++
   - desc: "`#warning`"
     paper: N2686
     support:
@@ -247,6 +248,7 @@ features:
       - tool: Xcode
         status: partial
         note: "Supported as an extension. Missing support for scalars and variable-length arrays (VLAs)."
+      - R++
   - desc: "`typeof` and `typeof_unqual`"
     paper:
       - N2927
@@ -268,6 +270,7 @@ features:
       - GCC 13
       - Clang 16 (partial)
       - Xcode 16.1
+      - R++
   - desc: "Predefined `true` and `false`"
     paper: N2935
     content: c-bool-true-false.md
@@ -275,11 +278,14 @@ features:
       - GCC 13
       - Clang 15
       - Xcode 16.1
+      - R++
   - desc: "`[[unsequenced]]` and `[[reproducible]]`"
     paper: N2956
     content: c-unreachable.md
     support:
       - GCC 15
+      - tool: R++
+        status: unsupported
   - desc: "Relax requirements for [variadic parameter list](https://cppreference.com/c/language/variadic)"
     paper: N2975
     support:
@@ -293,6 +299,7 @@ features:
       - GCC 13
       - Clang 18
       - Xcode 16.4
+      - R++ 2023.3
   - desc: "`#embed`"
     paper: N3017
     content: c-embed.md
@@ -308,6 +315,7 @@ features:
       - GCC 13
       - Clang 19
       - Xcode 16.4
+      - R++ 2024.2
   - desc: "Improved Normal Enumerations"
     paper: N3029
     support:
@@ -349,9 +357,11 @@ features:
       - GCC 13
       - Clang 16 (partial)
       - Xcode 16.1
+      - R++
   - desc: "Partial program correctness"
     paper: N3128
     support:
       - tool: GCC
         status: partial
         note: "Not guaranteed for volatile accesses"
+      - R++
diff --git a/features_c99.yaml b/features_c99.yaml
index ba6114d..33b447d 100644
--- a/features_c99.yaml
+++ b/features_c99.yaml
@@ -7,6 +7,7 @@ features:
       - Clang
       - MSVC
       - Xcode
+      - R++
     content: c-universal-character-names.md
   - desc: "Increased [translation limits](https://cppreference.com/c/language/identifiers#Translation_limits)"
     summary: "Raised minimum translation limits for portable programs."
@@ -17,6 +18,7 @@ features:
       - Xcode
       - owcc
       - TinyCC
+      - R++
     content: c-translation-limits.md
   - desc: "`//` comments"
     paper: N644
@@ -28,6 +30,7 @@ features:
       - Xcode
       - owcc
       - TinyCC
+      - R++
   - desc: "`restrict` pointers"
     paper: N448
     content: c-restrict.md
@@ -74,6 +77,7 @@ features:
       - Clang
       - Xcode 14
       - TinyCC
+      - R++
   - desc: "[Variably-modified](https://cppreference.com/c/language/array#Variable-length_arrays) (VM) types"
     paper: N683
     content: c-vm-types.md
@@ -82,6 +86,7 @@ features:
       - Clang
       - Xcode
       - TinyCC 0.9.28
+      - R++
   - desc: "Designated initializers"
     paper: N494
     content: c-designated-init.md
@@ -91,6 +96,7 @@ features:
       - MSVC
       - Xcode 14
       - owcc 1.4
+      - R++
   - desc: "Non-constant initializers"
     summary: "Non-constant initializers for block-scope aggregates."
     support:
@@ -98,6 +104,7 @@ features:
       - tool: owcc
         status: partial
         note: "Requires -aa for wcc*."
+      - R++
     content: c-non-constant-initializers.md
   - desc: "Idempotent cvr-qualifiers"
     summary: "Repeated cvr-qualifiers on a type are idempotent."
@@ -106,6 +113,8 @@ features:
       - GCC 3
       - Clang
       - Xcode
+      - tool: R++
+        status: unsupported
     content: c-idempotent-qualifiers.md
   - desc: "Trailing comma in _enumerator-list_"
     summary: "A comma is allowed after the last enumerator."
@@ -116,6 +125,7 @@ features:
       - Xcode
       - owcc
       - TinyCC
+      - R++
     content: c-enum-trailing-comma.md
   - desc: "Hexadecimal [floating constants](https://cppreference.com/c/language/floating_constant)"
     paper: N308
@@ -151,6 +161,7 @@ features:
       - GCC
       - Clang
       - Xcode
+      - R++
     content: c-integer-division-truncation.md
   - desc: "Implicit `return 0;` in the [`main()` function](https://cppreference.com/c/language/main_function)"
     summary: "Reaching the end of `main` returns zero implicitly."
@@ -161,6 +172,7 @@ features:
       - Xcode
       - owcc 1.5
       - TinyCC
+      - R++
     content: c-implicit-return-main.md
   - desc: "Declarations and statements in mixed order"
     summary: "Declarations and statements may interleave within a block."
@@ -172,6 +184,7 @@ features:
       - Xcode 14
       - owcc
       - TinyCC
+      - R++
     content: c-mixed-declarations.md
   - desc: "_init-statement_ in `for` loops"
     summary: "Declaring loop counters in a `for` statement's init clause."
@@ -182,6 +195,7 @@ features:
       - Xcode
       - owcc
       - TinyCC
+      - R++
     content: c-for-loop-declarations.md
   - desc: "`inline` functions"
     paper: N741
@@ -193,6 +207,7 @@ features:
       - Xcode 14
       - owcc 1.3
       - TinyCC
+      - R++
   - desc: "Predefined variable `__func__`"
     paper: N611
     content: c-func.md