diff --git a/tools/singularity/README.md b/tools/singularity/README.md
index 3f7b69d409..bd13d75ad7 100644
--- a/tools/singularity/README.md
+++ b/tools/singularity/README.md
@@ -10,12 +10,6 @@ workstation, e.g. when bugs are reported that can only be reproduced on
 a specific OS or with specific (mostly older) versions of tools,
 compilers, or libraries.
 
-Ready-to-use container images built from some these definition files are
-occasionally uploaded to the container library at sylabs.io. They
-can be found here: https://cloud.sylabs.io/library/lammps/default/lammps_development#
-and will be signed with a GPG key that has the fingerprint:
-EEA103764C6C633EDC8AC428D9B44E93BF0C375A
-
 Here is a workflow for testing a compilation of LAMMPS with a locally
 built CentOS 7.x singularity container.
 
@@ -30,34 +24,3 @@ cmake -C ../cmake/presets/most.cmake ../cmake
 make
 ```
 
-And here is the equivalent workflow for testing a compilation of LAMMPS
-using a pre-built Ubuntu 18.04LTS singularity container.
-
-```
-cd some/work/directory
-git clone --depth 500  git://github.com/lammps/lammps.git lammps
-mkdir build-ubuntu18
-cd build-ubuntu18
-singularity pull library://lammps/default/lammps_development:ubuntu18.04
-singularity exec lammps_development_ubuntu18.04.sif bash --login
-cmake -C ../cmake/presets/most.cmake ../cmake
-make
-```
-
-| Currently available:           | Description                                    |
-| ------------------------------ | ---------------------------------------------- |
-| centos7.def                    | CentOS 7.x with EPEL enabled, no LaTeX         |
-| centos8.def                    | CentOS 8.x with EPEL enabled                   |
-| fedora34_mingw.def             | Fedora 34 with MinGW cross-compiler toolchain  |
-| ubuntu16.04.def                | Ubuntu 16.04LTS with MPI == OpenMPI, no LaTeX  |
-| ubuntu18.04.def                | Ubuntu 18.04LTS with MPI == OpenMPI            |
-| ubuntu18.04_amd_rocm.def       | Ubuntu 18.04LTS with AMD ROCm toolkit          |
-| ubuntu18.04_gpu.def            | Ubuntu 18.04LTS with -"- plus Nvidia CUDA 11.0 |
-| ubuntu18.04_nvidia.def         | Ubuntu 18.04LTS with Nvidia CUDA 11.0 toolkit  |
-| ubuntu18.04_intel_opencl.def   | Ubuntu 18.04LTS with Intel OpenCL runtime      |
-| ubuntu20.04.def                | Ubuntu 20.04LTS with MPI == OpenMPI            |
-| ubuntu20.04_amd_rocm.def       | Ubuntu 20.04LTS with AMD ROCm toolkit          |
-| ubuntu20.04_gpu.def            | Ubuntu 20.04LTS with -"- plus Nvidia CUDA 11.0 |
-| ubuntu20.04_nvidia.def         | Ubuntu 20.04LTS with Nvidia CUDA 11.0 toolkit  |
-| ubuntu20.04_intel_opencl.def   | Ubuntu 20.04LTS with Intel OpenCL runtime      |
-| ------------------------------ | ---------------------------------------------- |