The words that are not variable assignments or redirections shall be expanded. If any fields remain following their expansion, the first field shall be considered the command name and remaining fields are the arguments for the command. If the command name is recognized as a declaration utility, then any remaining words that would be recognized as a variable assignment in isolation shall be expanded as a variable assignment (tilde expansion after the first <equals-sign> and after any unquoted <colon>, parameter expansion, command substitution, arithmetic expansion, and quote removal, but no field splitting or pathname expansion); while words that would not be a variable assignment in isolation shall be subject to regular expansion. For all other command names, all subsequent words shall be subject to regular expansion (tilde expansion for only a leading <tilde>, parameter expansion, command substitution, arithmetic expansion, field splitting, pathname expansion, and quote removal).

The first word (if any) that is not a variable assignment or redirection shall be expanded. If any fields remain following its expansion, the first field shall be considered the command name. If no fields remain, the next word (if any) shall be expanded, and so on, until a command name is found or no words remain. If there is a command name and it is recognized as a declaration utility, then any remaining words after the word that expanded to produce the command name, that would be recognized as a variable assignment in isolation, shall be expanded as a variable assignment (tilde expansion after the first <equals-sign> and after any unquoted <colon>, parameter expansion, command substitution, arithmetic expansion, and quote removal, but no field splitting or pathname expansion); while remaining words that would not be a variable assignment in isolation shall be subject to regular expansion (tilde expansion for only a leading <tilde>, parameter expansion, command substitution, arithmetic expansion, field splitting, pathname expansion, and quote removal). For all other command names, words after the word that produced the command name shall be subject only to regular expansion. All fields resulting from the expansion of the word that produced the command name and the subsequent words, except for the field containing the command name, shall be the arguments for the command.