diff --git a/Sources/DocCArchive/Schema_0_1/Content/CodeListing.swift b/Sources/DocCArchive/Schema_0_1/Content/CodeListing.swift
index 510975d..a444548 100644
--- a/Sources/DocCArchive/Schema_0_1/Content/CodeListing.swift
+++ b/Sources/DocCArchive/Schema_0_1/Content/CodeListing.swift
@@ -9,12 +9,14 @@
 extension DocCArchive.DocCSchema_0_1.Content {
 
   public struct CodeListing: Equatable, CustomStringConvertible, Codable {
-    public var syntax : String
+    public var syntax : String?
     public var code   : [ String ]
     
     public var description: String {
-      return syntax.isEmpty ? "<Code #\(code.count)>"
-                            : "<Code[\(syntax)]: #\(code.count)>"
+        guard let syntax = syntax, !syntax.isEmpty else {
+            return "<Code #\(code.count)>"
+        }
+        return "<Code[\(syntax)]: #\(code.count)>"
     }
   }
 }
diff --git a/Sources/DocCArchive/Schema_0_1/Content/Content.swift b/Sources/DocCArchive/Schema_0_1/Content/Content.swift
index 84c55f7..a811f41 100644
--- a/Sources/DocCArchive/Schema_0_1/Content/Content.swift
+++ b/Sources/DocCArchive/Schema_0_1/Content/Content.swift
@@ -15,6 +15,10 @@ extension DocCArchive.DocCSchema_0_1 {
     
     public enum Style: String, Codable {
       case note
+      case warning
+      case important
+      case tip
+      case experiment
     }
     
     public struct Item: Equatable, Codable {
diff --git a/Sources/DocCArchive/Schema_0_1/InlineContent.swift b/Sources/DocCArchive/Schema_0_1/InlineContent.swift
index 84ddfc2..0c6e7b8 100644
--- a/Sources/DocCArchive/Schema_0_1/InlineContent.swift
+++ b/Sources/DocCArchive/Schema_0_1/InlineContent.swift
@@ -18,6 +18,7 @@ extension DocCArchive.DocCSchema_0_1 {
                    overridingTitleInlineContent : [ InlineContent ]?)
     case image    (identifier: String)
     case emphasis ([ InlineContent ])
+    case strong   ([ InlineContent ])
     case codeVoice(code: String)
     
     public var description: String {
@@ -27,6 +28,7 @@ extension DocCArchive.DocCSchema_0_1 {
           return "\(id)\(isActive ? "" : "-inactive")"
         case .image    (let id)      : return "<img \(id)>"
         case .emphasis (let content) : return "*\(content)*"
+        case .strong   (let content) : return "**\(content)**"
         case .codeVoice(let code)    : return "`\(code)`"
       }
     }
@@ -54,6 +56,9 @@ extension DocCArchive.DocCSchema_0_1 {
         case "emphasis":
           self = .emphasis(try container.decode([ InlineContent ].self,
                                                 forKey: .inlineContent))
+        case "strong":
+          self = .strong(try container.decode([ InlineContent ].self,
+                                              forKey: .inlineContent))
         case "reference":
           self = .reference(
             identifier:
@@ -90,6 +95,9 @@ extension DocCArchive.DocCSchema_0_1 {
         case .emphasis(let content):
           try container.encode("emphasis"  , forKey: .type)
           try container.encode(content     , forKey: .inlineContent)
+        case .strong(let content):
+          try container.encode("strong"    , forKey: .type)
+          try container.encode(content     , forKey: .inlineContent)
         case .reference(let identifier, let isActive, let ot, let otc):
           try container.encode("reference" , forKey: .type)
           try container.encode(identifier  , forKey: .identifier)
diff --git a/Tests/DocCArchiveTests/DocumentDecodingTests.swift b/Tests/DocCArchiveTests/DocumentDecodingTests.swift
index 3f81df8..ef9d5a8 100644
--- a/Tests/DocCArchiveTests/DocumentDecodingTests.swift
+++ b/Tests/DocCArchiveTests/DocumentDecodingTests.swift
@@ -18,9 +18,40 @@ final class DocumentDecodingTests: XCTestCase {
     ( "testIssue10FailTypeMethodRoleHeading",
       testIssue10FailTypeMethodRoleHeading ),
     ( "testIssue11FailUnorderedList"    , testIssue11FailUnorderedList    ),
-    ( "testAllDataJSONInSlothCreator"   , testAllDataJSONInSlothCreator   )
+    ( "testAllDataJSONInSlothCreator"   , testAllDataJSONInSlothCreator   ),
+    ( "testIssue12FailAsideWarningStyle", testIssue12FailAsideWarningStyle )
   ]
-  
+
+  func testIssue12FailAsideWarningStyle() throws {
+    let url  = Fixtures.baseURL.appendingPathComponent("Issue12Fail.json")
+    let data = try Data(contentsOf: url)
+
+    let document : DocCArchive.Document
+
+    print("Decoding:", url.path)
+    do {
+      document = try JSONDecoder().decode(DocCArchive.Document.self, from: data)
+
+      guard let section = document.primaryContentSections?.first else {
+        XCTAssert(false, "did not find primary content section"); return
+      }
+      guard case .content(let contents) = section.kind else {
+        XCTAssert(false, "did not find content section"); return
+      }
+      guard case .aside(style: let style, content: let asideContents) = contents.dropFirst().first else {
+        XCTAssert(false, "did not find aside"); return
+      }
+      XCTAssertEqual(style, .warning, "expected to find warning")
+      XCTAssert(asideContents.count == 1)
+    }
+    catch {
+      print("ERROR:", error)
+      XCTAssert(false, "failed to decode: \(error)")
+      return
+    }
+    XCTAssertEqual(document.schemaVersion, .init(major: 0, minor: 1, patch: 0))
+  }
+
   func testIssue11FailUnorderedList() throws {
     let url  = Fixtures.baseURL.appendingPathComponent("Issue11Fail.json")
     let data = try Data(contentsOf: url)
diff --git a/Tests/DocCArchiveTests/Fixtures/Issue12Fail.json b/Tests/DocCArchiveTests/Fixtures/Issue12Fail.json
new file mode 100644
index 0000000..1cdf609
--- /dev/null
+++ b/Tests/DocCArchiveTests/Fixtures/Issue12Fail.json
@@ -0,0 +1,61 @@
+{
+  "primaryContentSections": [
+    {
+          "kind": "content",
+          "content": [
+            {
+              "anchor": "discussion",
+              "level": 2,
+              "type": "heading",
+              "text": "Discussion"
+            },
+            {
+              "type": "aside",
+              "style": "warning",
+              "content": [
+                {
+                  "type": "paragraph",
+                  "inlineContent": [
+                    {
+                      "type": "text",
+                      "text": "Values above "
+                    },
+                    {
+                      "type": "codeVoice",
+                      "code": "99"
+                    },
+                    {
+                      "type": "text",
+                      "text": " will be shown as "
+                    },
+                    {
+                      "type": "codeVoice",
+                      "code": "99+"
+                    },
+                    {
+                      "type": "text",
+                      "text": "."
+                    }
+                  ]
+                }
+              ]
+            }
+          ]
+        }
+  ],
+  "schemaVersion":{"major":0,"minor":1,"patch":0},
+  "identifier":{
+    "url":"doc://ARI/documentation/Fail12",
+    "interfaceLanguage":"swift"
+  },
+  "kind":"symbol",
+  "metadata": {
+    "title": "And then she kissed her",
+    "categoryPathComponent": "Songs",
+    "role": "project",
+    "category": "Songs"
+  },
+  "hierarchy":{ "paths":[] },
+  "sections":[],
+  "references":{}
+}