Fair and equitable treatment/Minimum standard of treatment, including denial of justice claims
Full protection and security, or similar
Most-favoured nation treatment
Arbitrary, unreasonable and/or discriminatory measures
http://globalarbitrationreview.com/news/article/31604/peru-fends-off-argentine-treaty-claim/ (requires subscription)
http://globalarbitrationreview.com/news/article/27742/new-claim-against-peru-terminated-highway-contract/ (requires subscription)