【Sign】 ,  【mark】 ,  【token】 ,  【badge】 ,  【note】 ,  【symptom】  can denote a sensible and usually visible indication by means of which something not outwardly apparent or obvious is made known or revealed.

【Sign】  is the most comprehensive of these terms, being referable to a symbol (see also CHARACTER 1 ) or a symbolic device or act or to a visible or sensible manifestation of a mood, a mental or physical state, or a quality of character or to a trace or vestige of someone or something or to objective evidence that serves as a presage or foretoken and concretely to a placard, board, tablet, or card that serves to identify, announce, or direct.

【Mark】  (see also CHARACTER 1 ) may be preferred to  【sign】 when the distinguishing or revealing indication is thought of as something impressed upon a thing or inherently characteristic of it, often in contrast to something outwardly apparent or displayed.

Concretely also  【mark】 is applied either (1) to some visible trace (as a scar or a stain or a track) left upon a thing or (2) to something that is affixed in order to distinguish, identify, or label a particular thing or to indicate its ownership.

【Token】  (see also PLEDGE ) can replace  【sign】  and also  【mark】 except in their specific concrete applications when the sensible indication serves as a proof of or is given as evidence of the actual existence of something that has no physical existence.

【Badge】 designates a piece of metal or a ribbon carrying an inscription or emblem and worn upon the person as a 【token】 of one’s membership in a society or as a 【sign】 of one’s office, employment, or function.

In extended use  【badge】  often is employed in place of  【sign】 ,  【mark】 , or  【token】 when it is thought of in reference to a class, a group, a category of persons, or as a distinctive feature of their dress, their appearance, or their character.

【Note】  usually means a distinguishing or dominant 【mark】 or characteristic; it differs from  【mark】 , its closest synonym, in suggesting something emitted or given out by a thing, rather than something impressed upon that thing.

【Note】  may be used in place of  【mark】 for a characteristic that seems to emanate from a thing that strikes one as true or authentic and therefore is the test of a similar thing’s truth, genuineness, or authoritativeness.

【Symptom】  can apply to any of the physical or mental changes from the normal which can be interpreted as evidence of disease, but in medical use it is commonly restricted to the subjective evidences of disease primarily apparent to the sufferer and is then opposed to  【sign】 , which is applied to the objective evidences of abnormality that are primarily determined by tests and instruments.

In extended use the term tends to follow popular rather than professional medical use and is applicable to an outward indication of an inner change (as in an institution, a state, or the body politic) or to an external phenomenon that may be interpreted as the result of some internal condition (as a weakness, defect, or disturbance).