Martyn Underhill, ICVAs Chair has recorded a thank you message for all of the dedicated Custody Visitors who are volunteers, visiting detainees in police custody to ensure their rights, entitlements and wellbeing. Volunteers Week 2018. You can keep up to date with everything ICVA is doing to raise awareness for the week on this site and by following @custodyvisiting and @projectICVA on Twitter. Happy volunteer week and thank you.