2023 Washington Code 18.106.070 – Certificates of competency, installer endorsement — Issuance — Renewal — Rights of holder — Training certificates — Supervision — Training, certified plumber — Work group

2022 Washington Code 18.106.070 – Certificates of competency, installer endorsement–Issuance–Renewal–Rights of holder–Training certificates–Supervision–Training, certified plumber–Work group

2020 Washington Code 18.106.070 – Certificates of competency, installer endorsement — Issuance — Renewal — Rights of holder — Training certificates — Supervision — Training, certified plumber — Work group

2019 Washington Code 18.106.070 – Certificates of competency, installer endorsement — Issuance — Renewal — Rights of holder — Training certificates — Supervision — Training, certified plumber

2018 Washington Code 18.106.070 – Certificates of competency, installer endorsement — Issuance — Renewal — Rights of holder — Training certificates — Supervision — Training, certified plumber

2016 Washington Code 18.106.070 – Certificates of competency, installer endorsement–Issuance–Renewal–Rights of holder–Training certificates–Supervision–Training, certified plumber

2015 Washington Code 18.106.070 – Certificates of competency, installer endorsement–Issuance–Renewal–Rights of holder–Training certificates–Supervision–Training, certified plumber

2014 Washington Code 18.106.070 – Certificates of competency, installer endorsement — Issuance — Renewal — Rights of holder — Training certificates — Supervision — Training, certified plumber

2013 Washington Code 18.106.070 – Certificates of competency, installer endorsement — Issuance — Renewal — Rights of holder — Training certificates — Supervision — Training, certified plumber

2009 Washington Code 18.106.070 – Certificates of competency, installer endorsement — Issuance — Renewal — Rights of holder — Training certificates — Supervision — Training, certified plumber