Can flexible conductors without ferrules be connected to terminals blocks?

Klippon® Connect SNAP IN Terminal Blocks - Weidmuller

Assemble circular connectors with M12 Push-Lock technology

JANDECCN 50 Pack DIN Rail Terminal Blocks, Compact Wire Conductor Wiring Connectors for 24-12 AWG: : Industrial & Scientific

Spring connection

Ferrules: What They Are And How They're Used - News

Use of Cable Ferrule Electricity Turkey Magazine

3D Printer Electrical Wiring: A DIY Guide

Should I crimp this stranded wire with ferrule before using the splice connector or just directly using the connector? (More details in comment) : r/AskElectronics

UC series Cabur: flying lever terminal block

Push-in connection for terminal blocks

What is a Wire Ferrule?