A [Formula: see text]-[Formula: see text]-[Formula: see text]-[Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] is a mapping [Formula: see text] such that [Formula: see text] for any three consecutive edges [Formula: see text],[Formula: see text],[Formula: see text] of a path or a [Formula: see text]-cycle. [Formula: see text][Formula: see text] has a [Formula: see text]-injective-edge-coloring[Formula: see text] is called the [Formula: see text]. In this paper, we prove that for planar graphs [Formula: see text] with [Formula: see text], (1)[Formula: see text] if [Formula: see text]; (2)[Formula: see text] if [Formula: see text].

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A strong[Formula: see text]-edge-coloring of a graph [Formula: see text] is a mapping [Formula: see text]: [Formula: see text], such that [Formula: see text] for every pair of distinct edges at distance at most two. The strong chromatical index of a graph [Formula: see text] is the least integer [Formula: see text] such that [Formula: see text] has a strong-[Formula: see text]-edge-coloring, denoted by [Formula: see text]. In this paper, we prove [Formula: see text] for any subcubic planar graph with [Formula: see text] and [Formula: see text]-cycles are not adjacent to [Formula: see text]-cycles.