'Discussions' regarding which term is appropriate for certain firearm loading devices and cartridge holders are certainly not new and will surely go on for generations.

Notice the apparent contradictions in this larger detail from the '39 Stoeger:

I assume that by 'clip only' they meant that the price did not include cartridges.

All are listed as "clips" with only the M88's en bloc being also referred to as a "magazine". The Lebel, Mannlicher M95, and M93 are also en bloc.

The M1 Garand used en bloc, and to GI's in the field they were 'clips'. This Stoeger catalog of 1939, however, shows that Yanks were already using the word 'clip' to describe them before WW2.

Folks worldwide have differing opinions regarding what is and is not a 'clip'. Though often and generally referred to as a 'clip' the loading device for the M88 is, by definition, an en bloc. En bloc translates to 'all together' or 'as a unit' which is how they are installed into the firearm to become an integral part of the magazine during use. With the last shot fired, they are ejected. This was the Mannlicher 'packet loading' system. Perhaps a better English language term for en bloc would be 'packets'?

Such operation is rather different from that of a Mauser type 'stripper clip' or 'charger' which is used only to feed a magazine and is not a part of the arm when fired, or of a 'box magazine' as used with Thompson SMG's and the Colt 1911.

Here's a fairly concise explanation (opinion?) -
FirearmsHistory