def parse_mods(modifications, psimod_mapping=None):
    """
    Convert mzTab modifications to MS2PIP PEPREC modifications.

    N-term and C-term modifications are not supported!
    Entries without modifications should be given as '-'

    modifications - Pandas Series containing mzTab-formatted modifications
    psimod_mapping - dictionary that maps PSI-MOD entries to desired modification names
    """
    if not psimod_mapping:
        psimod_mapping = psimod_mapping = {
            'MOD:00394': 'Acetyl',
            'MOD:00400': 'Deamidated',
            'MOD:00425': 'Oxidation',
            'MOD:01214': 'Carbamidomethyl'
        }

    parsed_mods = []
    for mods in modifications.fillna('-').str.split(',|-'):
        if mods == ['', '']:
            parsed_mods.append('-')
        else:
            pos = [str(int(p) + 1) for p in mods[::2]]
            names = [psimod_mapping[n] for n in mods[1::2]]
            parsed_mods.append('|'.join(['|'.join(i) for i in list(zip(pos, names))]))

    return parsed_mods