What degree of mastery of this language should one strive for as a student, legal assistant, or lawyer?
Recall that a citation serves several purposes. Of those purposes, one is paramount furnishing accurate and complete information that will enable retrieval of the cited document or document part. The element of citation that calls for immediate mastery is painstaking care in recording and presenting the complete address or retrieval ID of a document. Citing a case using the wrong volume or page number, citing a statute with an erroneous section number or without a necessary title number errors like these cannot be explained away by the intricacies of citation. Their negative impact on readers is palpable. Consider the frustration you experience when you are given an erroneous or partial street address or an email address that fails because of a typo; a judge's reaction to an erroneous citation is likely to be quite similar.
Since, in many cases, part of the clear address to a cited document includes an abbreviation, a small set of abbreviations must be mastered as soon as possible. A minimum set includes those that represent the reporters for contemporary federal decisions, those that represent codified federal statutes and regulations, and those that represent the regional reporters of state decisions. Whenever your research is centered in the law of a particular state, you will want also to memorize the abbreviations that represent the case reports, statutory compilations, and regulations of that state.
Less critical in terms of function but no more difficult to master are the abbreviations that indicate the deciding court when that information is not implicit in the name of the reporter. You should strive to master the abbreviations for the circuits of the U.S. Courts of Appeals and those for the U.S. District Courts. Any time your research is centered in the law of a particular state you will want to master the abbreviations for its different courts.
Last and least are the conventions for reducing the space consumed by case names and journal titles. Including the full word "Environmental" in a case name rather than the abbreviation "Envtl." is, standing by itself, a trivial oversight. A consistent failure to abbreviate on the one hand or the use of idiosyncratic or inconsistent abbreviations on the other can produce inconvenience for the reader. Since your aim in nearly all law writing will be to persuade your reader, to win your reader over, you do not want to irritate or to convey an impression of carelessness. Therefore, a final review of one's citations against the standard abbreviations and omissions set forth in one or the other of the dominant manuals is an important step. In time, you will find that you have internalized most of those rules.
Writing legal citation follows thorough legal research. As you carry out your research, your notes should capture all the information you will need to write the necessary citations. That entails recording all the required items for a full citation. It doesn't mean that you should take the time in the midst of research to check proper abbreviations; that can be a later step. What you will want to achieve, as soon as possible, is knowledge of what information elements will be required in a full citation. Knowing what to note at the time you do your research will save you from having to pay return visits to sources simply to determine which circuit decided a particular case, what paragraph or page numbers are associated with the portion of a decision supporting your point, or how recently the statutory compilation on which you are relying was updated.
Learning to read legal citation should be your first goal. Since you are surrounded by citations in any cases or articles you read, that should be easy. Even this requires an active frame of mind, however; it is easy to skim past citations. As you read legal material exercise your growing command of legal citation by asking yourself occasionally about a cited source: What is it? How would I retrieve it? And when you are reading in an environment that permits ready access to cases, statutes or other cited material and you are curious about a point on which there are cited references (or your head simply needs a change of pace) follow a citation or two. Reading and following citations should not require use of a manual.
Ultimately you will be able to write most citations without use of this reference or a manual most but not all. The old and the unusual will drive even the most experienced legal writer back to the pages of The Bluebook or the ALWD Citation Manual and, in states where one exists, a local citation guide.