About abbreviated commands: there is a few rules that describes how abbreviate SCPI commands elements (words) - how to create mnemonics
1. Key word which length equals 4 or smaller are also mnemonics: Free -> FREE Auto -> AUTO
2. If You have word with length greater than 4, mnemonic equals the first four chars
Frequency -> FREQ
Voltage -> VOLT
3. If key word ends with vocal mnemonic equals first three chars Power -> POW Attenuation -> ATT
4. for key words described by phrase, mnemonics are build using first char from first word and second key word mnemonic Direct Sequence -> DSeqence -> DSEQ Negative Transition -> NTranstion -> NTR