[...] the commentary on Canon 1250 from: A COMMENTARY ON THE NEW CODE OF CANON LAW By THE REV. P. CHAS. AUGUSTINE O.S.B., D.D., published in 1918
Thanks for the detailed citation. A recent Internet search didn't find such a detailed citation, never mind actual
content on line, so I suppose what you posted, you had to transcribe via your own keyboard.
The law of abstinence forbids the eating of flesh meat and broth or soup made of meat ; but it does not forbid cggs, lacticinia, and seasoning with fat of animals.
The new law here is milder than the old, for lacticinia were not always permitted by the Church, as may be seen from some Constitutions of Benedict XIV.
I suppose a reduction via Canon Law in the disciplinary ways for the faithful to sin is a
good thing in this instance.
The term lacticinia includes everything that is produced from milk, as well as the milk itself,--cheese, butter, margarine, etc. These, therefore, may be used even on days of abstinence. Fat of animals was defined as the fat, grease, or lard of any animal, not only of hogs.
Hmmm. "
lacticinia": I
do try to learn something new every day. The word is apparently a
postclassical Latin plural.
But back to my primary reason for posting: Let's not publicly overlook a source of information that's readily available to readers here, who
(m?) we already know have connections to the Internet:
        <
www.newadvent.org/cathen/01067a.htm>:
Abstinence
Adam's disobedience rendered all men criminal, and liable to the necessity of appeasing God's justice. To meet this new exigency nature dictated the necessity of penance; [....] The chief results of this determination are positive statutes concerning fasting and abstinence. Laws relating to fasting are principally intended to define what pertains to the quantity of food allowed on days of fasting, while those regulating abstinence, what refers to the quality of viands. In some instances both obligations coincide; thus, the Fridays of Lent are days of fasting and abstinence. In other instances the law of abstinence alone binds the faithful; thus ordinary Fridays are simply days of abstinence.
The purpose of this article is to trace the history of ecclesiastical legislation regarding the law of abstinence, as well as to examine the motives which underlie this legislation.
So the article is quite a bit longer and more detailed than would be practical for inscriptions on stone tablets or metal sheets.
[§] Application of the law in the United States
Diversity in customs, in climate, and in prices of food have gradually paved the way for modifications of the law of abstinence. Throughout the United States the ordinary Saturday is no longer a day of abstinence. During Lent, in virtue of an indult, the faithful are allowed to eat meat at their principal meal on Mondays, Tuesdays, Thursdays, and Saturdays, the second and last Saturdays excepted. The use of meat on such days is not restricted to the principal meal for such as are exempt from fasting by reason of ill health, age, or laborious occupations.  [Much more ...]
There's no direct
- link to this section, altho' it's an excellent example of a C.E. page that would benefit from them.
Eggs, milk, butter, and cheese, formerly prohibited, are now permitted without restriction as far as the day of the week is concerned. The use of lard or dripping in preparing fish and vegetables at all meals and on all days is allowed by an indult issued 3 August, 1887.  [Much more ...]
Ah! I knew I'd gotten this information from somewhere that I considered authoritative.
Odd that the source I cite below disagrees about fat of animals. I assume that's because the prevailing modern substantive meaning of "seasoning" seems to be "(thing) providing flavor", from the transitive verb:
1. To render palatable by adding salt, spice, or the like; hence to make pungent, piquant, etc. 
2. To treat by some process that will put it in[to] condition for use [....]
Where quoted definition 1. indicates that when REV. AUGUSTINE allows fat, he's allowing the faithful to enjoy the flavor of meat despite the plain prohibition against enjoying solid meat itself. That seems at odds with a "necessity of penance" that's based on knowingly limiting the "quality of viands" that's manifested, i.a., as flavor. And where I interpret quoted definition 2. as not being applied to edible items, but to inedible objects such as cast-iron cookware.
I suppose that with the last traditional Code of Canon Law having been promulgated in 1917 by Pope Benedict XV (1914--1922), your 1918 A COMMENTARY might outrank my 1907 source. Sigh.
For more brevity, 1 or more of the traditional catechisms that're on the Internet should suffice (at least, they usually do - , don't they?).
It also seems reasonable for other CathInfo members to offer links to relevant
individual postings in CathInfo's own
"The Library" forum (but remember that our owner-moderator has decreed:
"NO DISCUSSIONS ALLOWED [T]HERE ! ).
-------
Note *: I haven't done an
ad hoc review of those catechisms; in this instance, the
C.E. article seemed to meet my immediate needs.