The structure into which accredited qualifications are placed, allowing learners, training providers and employers to gain information about the broad equivalence of qualifications.
Source: UNESCO 1984, Global

A system for placing qualifications that meet certain standards of quality on one of a series of hierarchical levels.
Source: ILO 2006, Global

An instrument for the development and classification of qualifications (e.g. at national or sectoral level) according to a set of criteria (e.g. using descriptors) applicable to specified levels of learning outcomes.　
Source: CEDEFOP 2008, Europe

A structure for setting out the levels at which vocational qualifications accredited by regulatory authorities can be recognized.
Source: UNEVOC/NCVER 2009, Global

The hierarchical classification of the levels of formal learning programmes and their associated qualifications and certificates.(Comment: More advanced NQFs can also play a role in facilitating stakeholder interactions, creating coherent qualifications systems, ensuring fit-for-purpose qualifications, supporting wider quality assurance processes, recognizing learning gained outside formal education and training and for driving broader educational reforms. They also make national qualifications systems more transparent to
foreigners.)
Source: UNESCO 2015, Global