This improvement to trade pacts (B3.0) allows one additional FT added to each TP they have (ITP-II allows a second) above the limit in (B3.30). This additional FT may not be lent. Both parties must have this tech for the bonus FT to apply (and both would get the extra slot(s)). If one empire has level II of the tech while the other does not, only the bonus from level I applies.
This tech is only available after a successful R&D program (D1.0), but even after the success, it may not be produced before Y180. Additional R&D successes can reduce the inception date.
Example:
If the Gorns (10 major systems; level I) and Federation (20 major systems; level II) had this tech, instead of the normal 30 slots allowed by (B3.30), there would be 32. The Gorns could have as many as 11 slots assigned to them before the penalty described in (B3.45) kicked in. The UFP could similarly have up to 21. Once the Gorns attain level II, the 2nd bonus slot would be available to both.