Feature percolation conventions

Feature Percolation Conventions (FPCs) is a set of four mechanisms originally proposed in Lieber (1980) that copy the properties of words to the node that immediately dominates them. Lieber assumes that morphemes are inserted into unlabeled trees, and these trees are then labeled by means of the following FPCs:

(i)  FPC I:   All features of a stem morpheme, including category features, percolate to the first non-branching node dominating that morpheme. (ii) FPC II:  All features of an affix morpheme, including category features, percolate to the first branching node dominating that morpheme. (iii) FPC III: If a branching node fails to obtain features by FPC II, features from the next lowest labeled node automatically percolate up to the unlabeled branching node. (iv) FPC IV:  If two stems are sisters (i.e. they form a compound), features from the right-hand stem percolate up to the branching node dominating the stems.

Slightly different FPCs are proposed in Selkirk (1982) and DiSciullo &amp; Williams (1987). These alternative versions make use of the notions head and underspecification.

Link
Utrecht Lexicon of Linguistics