diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..40c7d27
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,45 @@
+# This file generated from a template file maintained in the ivoatex repository.
+# To create and install it into a project repository, do:
+#    make github-preview
+#    git commit
+#    git push
+#
+name: Check the IVOA document
+
+env:
+  doc_name:
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+
+    - name: Checkout the repository
+      uses: actions/checkout@v1
+      with:
+        submodules: true
+
+    - name: Setup dependencies
+      run: |
+        sudo apt update
+        sudo apt install texlive-latex-base texlive-latex-recommended texlive-latex-extra texlive-fonts-recommended xsltproc latexmk cm-super
+
+    - name: Build the document
+      run: make
+
+    - name: Check the output
+      run: |
+        test -f ${{ env.doc_name }}.pdf
+        test -f ${{ env.doc_name }}.bbl
+
+    - name: Keep the PDF artefact
+      uses: actions/upload-artifact@v1
+      with:
+        name: PDF Preview
+        path: ${{ env.doc_name }}.pdf
diff --git a/.github/workflows/preview.yml b/.github/workflows/preview.yml
new file mode 100644
index 0000000..cfbde8e
--- /dev/null
+++ b/.github/workflows/preview.yml
@@ -0,0 +1,66 @@
+# This file generated from a template file maintained in the ivoatex repository.
+# To create and install it into a project repository, do:
+#    make github-preview
+#    git commit
+#    git push
+#
+name: Update PDF Preview
+
+env:
+  doc_name:
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+
+    - name: Checkout the repository
+      uses: actions/checkout@v1
+      with:
+        submodules: true
+
+    - name: Setup dependencies
+      run: |
+        sudo apt update
+        sudo apt install texlive-latex-base texlive-latex-recommended texlive-latex-extra texlive-fonts-recommended xsltproc latexmk cm-super
+        sudo snap install pdftk
+
+    - name: Build the document
+      run: make ${{ env.doc_name }}-draft.pdf
+
+    - name: Check the output
+      run: |
+        test -f ${{ env.doc_name }}-draft.pdf
+        test -f ${{ env.doc_name }}.bbl
+
+    - name: Move the auto-pdf-preview tag
+      uses: weareyipyip/walking-tag-action@v2
+      with:
+        tag-name: auto-pdf-preview
+        tag-message: |
+          Last commit taken into account for the automatically updated PDF preview of this IVOA document.
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Update the PDF preview
+      uses: Xotl/cool-github-releases@v1
+      with:
+        mode: update
+        isPrerelease: true
+        tag_name: auto-pdf-preview
+        release_name: "Auto PDF Preview"
+        body_mrkdwn: |
+          This release aims to provide a PDF preview of the last commit applied on this repository.
+          It will be updated automatically after each merge of a PullRequest.
+          **DO NOT PUBLISH THIS PRE-RELEASE!**"
+          _Corresponding commit: ${{ github.sha }}_
+        assets: ${{ env.doc_name }}-draft.pdf
+        replace_assets: true
+        github_token: ${{ secrets.GITHUB_TOKEN }}
diff --git a/ObscoreTimeExtension.tex b/ObscoreTimeExtension.tex
index 8c618f1..361ed90 100644
--- a/ObscoreTimeExtension.tex
+++ b/ObscoreTimeExtension.tex
@@ -347,13 +347,13 @@ \subsection{Mentioning what part of the dataset varies with time }
   \begin{small}
   \begin{tabular}{|l|l|l|}
 \sptablerule
-\textbf{Main dataproduct\_type} & \textbf{o\_ucd}  &\textbf{time\_variant}   \\ \hline
+\textbf{Main dataproduct\_type} & \textbf{o\_ucd}  &\textbf{time\_variant component }   \\ \hline
 light curve & phot.flux &  scalar value \\ \hline
 velocity curve & doppler.veloc & scalar value \\ \hline 
 trajectory & pos.eq  &  sky position (vector) \\ \hline
-dynamic spectrum & phot.flux & dp:spectrum \\ \hline
-movie &   phot.flux & dp:image \\ \hline
-time cube & phot.flux & dp:cube \\ \hline
+dynamic spectrum & phot.flux & spectrum \\ \hline
+movie &   phot.flux & image \\ \hline
+time cube & phot.flux & cube \\ \hline
  \end{tabular}
   \end{small}
   \end{center}
@@ -405,8 +405,8 @@ \subsection{Mentioning what part of the dataset varies with time }
 
  \subsection{Time series uses cases already covered by ObsCore1.1}
  Several uses-cases for time series discoveries were considered in the ObsCore 1.1 specification, built on its short list of time related features.
-They are available in appendix A section A.4. Discovering time series . 
-Here the \emph{dataproduct\_type} value is "timeseries", very general, but the same uses cases can be applied for more specific time sampled datasets like "time-cube" or or "light-curve" available now in the \bf{product-type} vocabulary . 
+They are available in appendix A in section A.4. Discovering time series. 
+Here the \emph{dataproduct\_type} value is "timeseries", very general, but the same uses cases can be applied for more specific time sampled datasets like "time-cube" or or "light-curve" available now in the \textbf{product-type} vocabulary . 
 ObsCore uses cases are also provided  in a web page available at : \url{http://saada.unistra.fr/voexamples/show/ObsCore/}.
 
  \section{Time parameters proposed for Obscore Extension }