OzTransLtd opened the ticket and wrote:

There seems to be a problem with how OpenTTD handles GRM (GRF Resource Management); or is there something I don't know ?

Currently I use the following to reserve IDs for cargo types :

80 * 9 0D 03 00 FF 00 11 00 00 00
81 * 9 0D 03 00 03 FE FF 0B 01 00
82 * 9 0D 03 00 FF 00 2C 00 00 00
83 * 9 0D 03 00 03 FE FF 0B 01 00

the following messages are issued :

dbg: [grf] [Cansetw.grf:81] ParamSet: GRM: Reserving 1 cargos at 17
dbg: [grf] [Cansetw.grf:83] ParamSet: GRM: Reserving 1 cargos at 44

as a result of this, the set is green-flagged, but is not activated and none of the vehicles is available, neither are the rail construction menu items. Further there are more cargo reservations, which seem not be dealt with. The set seems to hang. Skipping the internal industry/cargo section activates the set and makes vehicles available.

from the wiki ...

For newcargos, IDs 00..1F refer to the cargo IDs themselves (e.g. ID 0B is available in the temperate climate, and 0C..1F in all climates), whereas IDs 20..3F refer to the bit number from prop. 08 plus 20 (e.g. ID 2D, being bit number 0D=fruit, is available in all climates except tropical). You need to check and mark both ID types for correct operation.

So my 0x11 reserves the cargo type for 'paper' and 0x2C reserves the same, but for the slot (+ 0x20) in the cargo translation table.

Reported version: trunk
Operating system: All

This issue was imported from FlySpray: https://bugs.openttd.org/task/1827