Normalize notes about "invalid" or "experimental" templates?

[amilan17]

134	This template was not validated at the time of publication and should be used with caution. Please report any use to the WMO Secretariat to assist for validation.

130	This template is experimental, was not validated at the time of publication and should be used only for bilateral previously agreed tests.
131	This template is experimental, was not validated at the time of publication and should be used only for bilateral previously agreed tests. (Octets 35-50 are very similar to octets 43-58 of product definition template 4.8, but the meaning of some fields differs slightly.)

Originally posted by @amilan17 in #118 (comment)