diff --git a/builder/package.rhel-9 b/builder/package.rhel-9
index a2b8cf4..9338288 100644
--- a/builder/package.rhel-9
+++ b/builder/package.rhel-9
@@ -8,13 +8,29 @@ if [[ "${R_VERSION}" =~ ^3 ]]; then
   pcre_lib='pcre-devel'
 fi
 
-# Create post-install script required for OpenBLAS
+# Create post-install script required for OpenBLAS.
+#
+# On RHEL and SUSE, we link R against the internal shared BLAS to make the
+# R binaries more portable and allow users to switch BLAS implementations without
+# having to recompile R. We default to OpenBLAS, but users may prefer other implementations.
+# 
+# Binary packages built against the shared BLAS are also more portable and may be used
+# with the default R distributed by RHEL/SUSE, or other R installations using
+# shared BLAS and configured with a different BLAS (such as Microsoft R Open with MKL).
+# This is especially important for RSPM's binary packages.
+#
+# On Ubuntu/Debian, we link R against the external BLAS instead (--with-blas/--with-lapack),
+# as those distributions use the alternatives system to swap BLAS libraries at runtime.
+# The default R distributions on Ubuntu/Debian use the external BLAS, so we do as well
+# for portability.
+#
+# https://cran.r-project.org/doc/manuals/r-release/R-admin.html#Shared-BLAS
 cat <<EOF >> /post-install.sh
 mv /opt/R/${R_VERSION}/lib/R/lib/libRblas.so /opt/R/${R_VERSION}/lib/R/lib/libRblas.so.keep
 ln -s /usr/lib64/libopenblasp.so /opt/R/${R_VERSION}/lib/R/lib/libRblas.so
 EOF
 
-# Create after-remove script to remove internal BLAS
+# Create after-remove script to remove internal BLAS, which won't be cleaned up automatically.
 cat <<EOF >> /after-remove.sh
 if [ -d /opt/R/${R_VERSION} ]; then
   rm -r /opt/R/${R_VERSION}