diff --git a/.travis.yml b/.travis.yml
index 4d0d798..4d90ea8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,5 @@
 language: java
+dist: trusty
 install: true
 
 services:
diff --git a/.unicornfig.yml b/.unicornfig.yml
index 94648f6..4f20a5a 100644
--- a/.unicornfig.yml
+++ b/.unicornfig.yml
@@ -7,5 +7,5 @@ description: "This repository contains the original interface definitions of pub
   \ definitions can provide a better understanding of HPI Cloud APIs and help you\
   \ to utilize them more efficiently. You can also use these definitions with open\
   \ source tools to generate client libraries, documentation, and other artifacts."
-version: "0.0.11"
+version: "0.0.12"
 githubName: "HPI-de/hpi-cloud-apis"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9091748..fdf97ba 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,11 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+## [0.0.12] - 2019-12-18
+### BREAKING CHANGES
+- **common, course, myhpi, news:** support different content types
+- **news:** normalize Article.categories, tags to IDs (repeated strings)
+
 ## [0.0.11] - 2019-10-06
 ### BREAKING CHANGES
 - **course:** add Course.attendance, enrollment_deadline; make CourseSeries.mandatory an enum
@@ -94,7 +99,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 Initial release with NewsService.
 
 
-[Unreleased]: https://github.com/HPI-de/hpi-cloud-apis/compare/0.0.11...dev
+[Unreleased]: https://github.com/HPI-de/hpi-cloud-apis/compare/0.0.12...dev
+[0.0.12]: https://github.com/HPI-de/hpi-cloud-apis/compare/0.0.11...0.0.12
 [0.0.11]: https://github.com/HPI-de/hpi-cloud-apis/compare/0.0.10...0.0.11
 [0.0.10]: https://github.com/HPI-de/hpi-cloud-apis/compare/0.0.9...0.0.10
 [0.0.9]: https://github.com/HPI-de/hpi-cloud-apis/compare/0.0.8...0.0.9
diff --git a/build.gradle b/build.gradle
index 2615ffe..4fe708d 100644
--- a/build.gradle
+++ b/build.gradle
@@ -35,7 +35,7 @@ ext {
     githubReleaseNotes = 'CHANGELOG.md'
     allLicenses = ["Apache-2.0"]
 
-    libraryVersion = "0.0.11"
+    libraryVersion = "0.0.12"
 }
 
 task sourcesJar(type: Jar, dependsOn: classes) {
diff --git a/hpi/cloud/common/v1test/markup_content.proto b/hpi/cloud/common/v1test/markup_content.proto
new file mode 100644
index 0000000..80d4a21
--- /dev/null
+++ b/hpi/cloud/common/v1test/markup_content.proto
@@ -0,0 +1,18 @@
+syntax = "proto3";
+
+package hpi.cloud.common.v1test;
+
+option java_multiple_files = true;
+option java_outer_classname = "MarkupContentProto";
+option java_package = "de.hpi.cloud.common.v1test";
+
+
+// Text in a markup format.
+message MarkupContent {
+  // Required. A MIME-type describing the content. Clients should support
+  // text/html and text/markdown.
+  string type = 1;
+
+  // Required. The actual content.
+  string content = 2;
+}
diff --git a/hpi/cloud/course/v1test/course.proto b/hpi/cloud/course/v1test/course.proto
index ebf3732..6e12fe4 100644
--- a/hpi/cloud/course/v1test/course.proto
+++ b/hpi/cloud/course/v1test/course.proto
@@ -4,6 +4,7 @@ package hpi.cloud.course.v1test;
 
 import "google/protobuf/wrappers.proto";
 import "google/type/date.proto";
+import "hpi/cloud/common/v1test/markup_content.proto";
 
 option java_multiple_files = true;
 option java_outer_classname = "CourseProto";
@@ -114,21 +115,21 @@ message CourseDetail {
   // Required. Programs this course can be graded in.
   map<string, ProgramList> programs = 3;
 
-  // A description (HTML).
-  string description = 4;
+  // A description.
+  hpi.cloud.common.v1test.MarkupContent description = 4;
 
-  // Requirements to participate in this course (HTML).
-  string requirements = 5;
+  // Requirements to participate in this course.
+  hpi.cloud.common.v1test.MarkupContent requirements = 5;
 
-  // What you'll learn by participating in this course (HTML).
-  string learning = 6;
+  // What you'll learn by participating in this course.
+  hpi.cloud.common.v1test.MarkupContent learning = 6;
 
-  // Which and how many exams take place (HTML).
-  string examination = 7;
+  // Which and how many exams take place.
+  hpi.cloud.common.v1test.MarkupContent examination = 7;
 
-  // When the course takes place (HTML).
-  string dates = 8;
+  // When the course takes place.
+  hpi.cloud.common.v1test.MarkupContent dates = 8;
 
-  // Additional literature for this course (HTML).
-  string literature = 9;
+  // Additional literature for this course.
+  hpi.cloud.common.v1test.MarkupContent literature = 9;
 }
diff --git a/hpi/cloud/myhpi/v1test/info_bit.proto b/hpi/cloud/myhpi/v1test/info_bit.proto
index 3852fd2..ce21b9e 100644
--- a/hpi/cloud/myhpi/v1test/info_bit.proto
+++ b/hpi/cloud/myhpi/v1test/info_bit.proto
@@ -3,6 +3,7 @@ syntax = "proto3";
 package hpi.cloud.myhpi.v1test;
 
 import "hpi/cloud/common/v1test/image.proto";
+import "hpi/cloud/common/v1test/markup_content.proto";
 
 option java_multiple_files = true;
 option java_outer_classname = "InfoBitProto";
@@ -28,8 +29,8 @@ message InfoBit {
   // Required. A short description.
   string description = 6;
 
-  // HTML-formatted content that can be set in addition to the description.
-  string content = 10;
+  // Content that can be set in addition to the description.
+  hpi.cloud.common.v1test.MarkupContent content = 10;
 
   // Different ways children are displayed within this info bit.
   enum ChildDisplay {
@@ -81,6 +82,6 @@ message LinkAction {
 }
 
 message TextAction {
-  // Required. The text to show (HTML).
-  string content = 1;
+  // Required. The text to show.
+  hpi.cloud.common.v1test.MarkupContent content = 1;
 }
diff --git a/hpi/cloud/news/v1test/article.proto b/hpi/cloud/news/v1test/article.proto
index df58079..1506510 100644
--- a/hpi/cloud/news/v1test/article.proto
+++ b/hpi/cloud/news/v1test/article.proto
@@ -5,6 +5,7 @@ package hpi.cloud.news.v1test;
 import "google/protobuf/timestamp.proto";
 import "google/protobuf/wrappers.proto";
 import "hpi/cloud/common/v1test/image.proto";
+import "hpi/cloud/common/v1test/markup_content.proto";
 
 option java_multiple_files = true;
 option java_outer_classname = "ArticleProto";
@@ -37,14 +38,14 @@ message Article {
   // Required. A short text summarizing this article. Recommended for a preview.
   string teaser = 8;
 
-  // Required. The actual HTML-content of this article.
-  string content = 9;
+  // Required. The actual content of this article.
+  hpi.cloud.common.v1test.MarkupContent content = 9;
 
-  // Categories of this article.
-  repeated Category categories = 10;
+  // IDs of categories of this article.
+  repeated string category_ids = 10;
 
-  // Tags of this article.
-  repeated Tag tags = 11;
+  // IDS of tags of this article.
+  repeated string tag_ids = 11;
 
   // The number of times this article was viewed.
   google.protobuf.UInt32Value view_count = 12;