This is the rei miro, a 'carved wooden pectoral in crescent form' (Van Tilburg). As wood was scarce on Easter Island, and therefore as precious as gold, it must be important. Something for the king to wear at important official events.

This type of glyph is written in periods nos. 5, 7, 18 and 24 (there twice). I think we may presume that these periods are characterized by important official events.

Only in this period (no. 7) does the sequence of glyphs start with rei miro. As main characters are introduced at the start, I guess this means that period no. 7 is of special importance for the king.