NML:Changes 0.3
From GRFSpecs
Introduction
Between NML 0.2.x and NML 0.3.x (and their corresponding nightlies) the generated NewGRF version by NML changed from v7 to v8. This brings lot of advantages, but requires a few changes to existing NML files. NewGRFs thus will require a minimum OpenTTD version of 1.2.0 (r23166).
Callbacks
NML 0.3 only supports the new style callbacks. Thus all callback_flag properties have been removed as have the callback flag constants *CBF*. For a complete list of affected constants see the related commit
Industry availability
The callback "availability" is no longer available. Use the callback "construction_probability" instead.