the corresponding LECs.

Anomalous processes start at $O(p^4)$. The odd-intrinsic-parity Lagrangian of $O(p^4)$ is given by the Wess-Zumino-Witten Lagrangian [@Wess:1971yu; @Witten:1983tw] that has no free parameters. The anomalous Lagrangian of $O(p^6)$ has 23 LECs [@Ebertshauser:2001nj; @Bijnens:2001bb]. Only partial results are available for the numerical values of those constants. The most promising approach is based on a short-distance analysis with or without chiral resonance Lagrangians [@Moussallam:1997xx; @Knecht:2001xc; @RuizFemenia:2003hm]. Electromagnetic corrections for anomalous processes ($n_f=2$) have also been investigated [@Ananthanarayan:2002kj].

The chiral Lagrangian for nonleptonic interactions of lowest order, $O(G_F p^2)$, contains two LECs $g_8,g_{27}$ [@Cronin:1967jq]. The most recent evaluation of these LECs, including isospin breaking corrections, can be found in the review [@Cirigliano:2011ny].

The LECs of $O(G_F p^4)$ (22 couplings $N_i$ in the octet and 28 couplings $D_i$ in the 27-plet Lagrangians) [@Kambor:1989tz; @Ecker:1992de] are less known than their strong counterparts at $O(p^4)$. The most recent phenomenological analysis of those combinations that occur in the dominant $K\to 2 \pi, 3 \pi$ decays can be found in Ref. [@Bijnens:2004ai]. Some of the LECs appearing in rare $K$ decays have also been analysed [@Cirigliano:2011ny].

Resonance saturation of weak LECs [@Ecker:1992de; @D'Ambrosio:1997tb] suffers from the drawback that the weak resonance couplings are unknown and 