Gifts: agricultural property: hope/development value
CG66960 told you that hold-over relief is available where agricultural property is disposed of which was not used for the purposes of a trade carried on by the donee. Relief is available if the asset transferred is agricultural property as defined in Section 115 IHTA 1984 and CG66961 told you how to confirm this.
Inheritance Tax agricultural property relief is available in respect of the agricultural value of the property transferred but not in respect of any hope or development value which is inherent in the property at the time of its transfer.
Capital Gains Tax hold-over relief is given by reference to the nature of the asset transferred not its value. If you are dealing with a case involving agricultural property you can allow hold-over relief on the whole of the gain, not just that part which reflects the agricultural value of the property transferred.