Vulnerable Persons Settlement precedent

I am trying to draft a Vulnerable Persons settlement for a client with a disabled adult son. I can only find a precedent in our rather out of date Sweet and Maxwell Practical Trusts Precedents ( Edited by Withers) volume which has a “Trust for the disabled” precedent from 1998! Apart from changing the Trust Period from 80 to 125 years and taking out references to 21 year Accumulation Period it contains the following reference under the Trustees shall not do the following provision

" so as to prevent the application of s 89 of the Inheritance [Tax] Act 1984 to these trusts during the lifetime of the Principal Beneficiary "

I intend to replace this with

“so as to prevent the application of Finance Act 2013 Schedule 44 ( or any amendment or re-enactment of that Schedule) to these trusts during the lifetime of the Principal Beneficiary”

Do forum members have any comment on this ( apart from telling me to get a more up to date precedent book!).

Nicholas Sewell
Bevirs