Quine expresses a position on understanding expressions that is pure Wittgenstein. Christopher Hookway expresses Quine’s and Wittgenstein’s position by writing that
"I understand an expression when I know the rule which governs its use and use it in accordance with that rule". 
In that case, rules take the place which abstract meanings had in much traditional philosophy. Instead of our understanding of an expression (or a statement) depending on that expression's meaning, we depend instead on its rule-of-use. More clearly, this rule will "govern its use". It tells us how we must use that expression.
Not only is this the case with understanding: the rule must make us "use the word" in accordance with it. Instead of meanings being of prime importance when it comes to understanding expressions, rules instead take that role.
Of course rules are very different things when compared to meanings.
Whereas rules tell us how to use an expression (or how they govern a word’s use), meanings don't tell us to do anything. In another sense, abstract meanings (taken in and of themselves) don't actually tell us anything. Instead, in terms of understanding an expression, what we must do is gain access to its meaning and then determine the actual nature of that meaning. A meaning, therefore, isn't normative in the way a rule is. If meanings don't determine the rules, we must use rules when using an expression. Then, in a sense, a meaning needs to be interpreted and understood; which is in opposition to the fact that rules aren't really interpreted at all (i.e., they're not abstract objects – they're linguistic).
Rules must also be understood in a different way.
If rules are always expressed linguistically and clearly, then there's a sense in which we can't go wrong in understanding and using them. Meanings, on the other hand, are either abstract objects or abstract mental entities. And if that's what they are, if they're something non-linguistic (when we first gain access to them), then there will be ways that make it the case that we could go wrong. The difference between a meaning and a rule would therefore be a little like an electrical device that comes with its instructions and one that does not. A meaning would be analogous in some way to the electrical device without instructions and the rule would correspond to the one that came with its own instructions.
Let's give an example of a linguistic rule in practice.
Take the expression 'cat'. In this case a conventional rule will tell us that this expression must always refer to a cat or to cats. We understand 'cat', then, when we accept the rule that tells us that it must be used to refer to cats. In terms of rules governing the actual use of the expression 'cat': they only apply in the situations in which we want other people to know that we're referring to (or talking about) a cat. We must only use 'cat' - and always use that word - when we want to refer to cats and also when we want to be understood by others as referring to a cat. And because this and all similar rules are both relatively strict and precise, then by definition it will rule out certain obvious - and not so obvious - mistakes in the use and understanding of 'cat'.
For example, we can't use the word to express our thought that "politicians are all liars". This is an obvious misuse of the word. However, neither can we use 'cat' to refer to only cats that are brown in colour. If that were the case, we would either require a new expression or a new rule. (In some cases we would require both.)
In terms of the misuses of the word 'cat' when it comes to understanding that word.
Clearly we can't take the rule to state that 'cat' is an expression that must always be used to express the fact that "cars are likely to crash on this road". In that case, we can say: "I don't like this road. It is a cat road." Clearly this is an extreme misunderstanding of the word 'cat' if we've already accepted the initial rules that explained to us how that word must be used and understood. However, we could misunderstand 'cat' and take it to be an expression that must always be taken as referring only to brown cats. And this would be the case according to the initial rule. It's clearly a misreading of that rule. In order for that word to be taken as always referring to brown cats, a new rule must be introduced that makes it the case that 'cat' only refers to brown cats. This, of course, would be a strange and unhelpful rule for the understanding and use of the word 'cat'. Yet it's in the nature of Wittgenstein's linguistic rules that a rule could be formulated by a particular convention or community that would indeed make it the case that within this convention or community the word 'cat' must always be understood as referring exclusively to brown cats. There's no logical reason that 'cat' couldn't be used in these counter-intuitive ways – that is, by people who were brought up on the original (our) understanding and rule for the word 'cat'!
This must also mean that it can't be the case that there are absolute, necessary or un-ignorable meanings that will make it the case that 'cat' must always be taken as an expression that can only refer to cats as a whole, not only to brown cats. This certainly is engendered by Wittgenstein’s philosophical position on abstract meanings and what he takes to be their nature.
But meanings aren't rules.
So how can meaning-realists talk in terms of 'absolute', 'necessary' or 'un-ignorable' meanings which we must abide by? How do the rules-of-use come from abstract meanings when there's no way in which they can say that an expression must be understood in such-and-such a way and must also be used in such-and-such a way? Such normative demands or rules couldn’t come from meanings themselves because they never tell us what must be the case: certainly not in the case of understanding linguistic expressions.
Strangely enough, even the meaning-realist all along must have been understanding 'cat' in a certain way and using that word in a particular way. Even he would admit that, like the Wittgensteinian, he too must use 'cat' in a certain way and he must understand it in a certain way. Even if we accepted the existence, and even the nature as stated by realists, of abstract meanings, we would still need to ask the meaning-realist where, exactly, his normative musts actually come from. In addition, what about the detailed rules that determine (in precise ways) both how 'cat' must be understood and how that word must be used? For the meaning-realist there would still be detailed rules - perhaps not actually called 'rules' - or simple standards that would tell him how he must understand and use certain expressions. In other words, there would still be normative aspects to his understanding and usage of expressions.
It's not the case, therefore, that a meaning-realist denies that there are linguistic rules of some kind that specify and determine our understandings and uses of expressions. Indeed how could he? He does differ from the Wittgensteinian, however, in two ways.
Firstly, he doesn't take rules to be as essential and important as the Wittgensteinian takes them to be. Instead he takes abstract meanings to be essential and important.
Secondly, the actual nature of rules would be seen differently by the meaning-realist. Perhaps he wouldn't even use the word 'rule'.
For example, he wouldn't take rules, and therefore conventions, to be quite so autonomous, contingent, and even arbitrary as he takes the Wittgensteinian to believe them to be. He would take rules (or some other normative notion) as themselves being dependent upon and determined by abstract meanings. In that case he may think that his rules would be less contingent and less autonomous than Wittgensteinian rules. Perhaps he wouldn't take them to be contingent at all.
Because of this possible meaning-realist's introduction of abstract meanings into this debate about linguistic rules, then many of the arguments he'd previously used about expressions and their meanings could now be applied to his position on rules. So just as abstract meanings both guaranteed and demanded universal, certain and necessary understandings and uses of expressions, now he may say similar things about his rules. He may now argue that rules themselves are universal, certain, necessary and determinate; just as the understandings and uses of expressions are of abstract meanings. Now he thinks that he can use and accept rules without - in the slightest respect -being a Wittgensteinian or a linguistic conventionalist.
We must again state what was stated earlier.
OK, I can accept the existence of abstract meanings. I can even accept the nature of meanings as you yourself have described them. For example, I can also provisionally accept that meanings are universal, certain, absolute and determinate. I can accept that such meanings also determine the linguistic rules to some extent. However, none of these provisional acceptances would - by themselves - allow me to use rules that have some kind of normative content - or even a lot of normative content.
Again, abstract meanings can't tell me how expressions must be understood and how they must be used in specific ways. Even the universal, certain and determinate properties of meanings couldn't determine rules expressed by normative modal terms like 'must'. And if these essential and important meanings, as you see them, determine the understandings, rules and uses of expression, then they still couldn't supply us with the normative content required for linguistic rules. If I accept at all that meanings determine expressions, understandings, uses and rules, I could only accept - even only provisionally - that they determine all these things in some kind of limited way. It would be a limited determination precisely because abstract meanings alone (whatever they're taken to be) can't determine the normative nature of our understandings and uses of expressions. And therefore also the normative nature of the rules which tell us how to understand and use expressions. All the arguments I've used about this limited nature of meanings, still apply despite your descriptions of the nature of meanings.
Where do rules really come from? They come from conventions and communities, according to Wittgenstein. They must therefore come from persons (or groups of persons). Now we can say that rules can't possibly come from anything that's essentially non-human or non-social. They can't come from abstract meanings, as argued. And precisely because of their normative nature, it can also be said that rules can't possibly come from anything that's non-human or non-social. The notion of normativity is applicable only to persons and, therefore, also to communities, conventions, institutions, etc. of persons. The rules too must express normative notions and display what an anti-Wittgensteinian may call anthropocentric properties.
Following on from that, the very idea that rules can somehow come from - or be determined by - abstract meanings is surely wrong. Indeed because rules are normative and normative notions are only applicable to persons and their creations, then saying that rules somehow and in some way come from meanings is as close to being a Rylian "category mistake" as anything could be.
The meaning-realist's position on meanings and rules is a very good example of Wittgenstein's claim that so many philosophers have attempted the task of transcending - or moving beyond - natural languages and the human world. In the case of the meaning-realist, he does so by stressing the essential and important nature of abstract meanings when it comes to rules and therefore to the understandings and usages of expressions. Clearly abstract meanings are neither linguistic nor personal. In that sense, the meaning-realist’s meanings transcend language and the human world. Indeed he would probably think it important that they should transcend language and the human world as a whole because such things can only offer us contingency, uncertainty, conventionality, particularity and all the other vices of the natural languages and the social world. Abstract meanings, on the other hand, offer us the exact antitheses of all these properties. And they do so precisely because they're taken to transcend language and the social.
The meaning-realist would accept that Wittgenstein is partly right in what he says about transcending or moving beyond language and the social. However, the difference would be that whereas Wittgenstein believed that such acts of transcendence are always futile precisely because they couldn't in fact be achieved; so our meaning-realist believes that acts of transcendence beyond language and the social are not only possible: they can be (or are) highly beneficial to philosophy. The meaning-realist's acts of language transcendence wouldn't be futile; as Wittgenstein argued they are.
Hookway, C – (1988) Quine, Polity Press
Wittgenstein, L (1953/1958) Philosophical Investigations, Oxford