Looking for mlperf docker container

Hello,
As I read the MLPerf training results 1.1 [1], the docker build command is not valid.

docker build --pull -t <docker/registry>/mlperf-nvidia:language_model .

What is <docker/registry> exactly?

[1] training_results_v1.1/NVIDIA/benchmarks/bert/implementations/pytorch at main · mlcommons/training_results_v1.1 · GitHub