You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
TECHNOLOGICAL FIELD 
     The technological field of the disclosure is residential construction and more particularly, construction of screened-in porches. 
     BACKGROUND 
     A porch is the extension of a house that is most exposed to the weather. A porch may be covered by a roof and is often enclosed by mesh screening attached to a framework. Porches can be comfortable much of the year in temperate climates. If the weather turns cold or windy and wet, then the comfort level decreases accordingly. Many homeowners tack plastic sheeting over the mesh screening of a screened-in porch during winter months may make the porch a little more comfortable. 
     Having a porch open on several sides may not be desirable even in warmer times of the year depending on the desire for privacy, the view, and perhaps the direction of the sun. For example, if adjacent homes are close, perhaps the view to the area behind the porch is agreeable but the view to the sides may simply underscore the closeness of adjacent homes. As another example, a porch with an eastern or western exposure may result in bright, hot morning or afternoon sun flooding the porch, making it uncomfortable despite otherwise moderate air temperatures. 
     Having the capability to modify the exposure of one or more sides of a porch by decreasing sunlight, providing protection from ultraviolet sunlight, weatherizing a porch, and adding a modicum of privacy would be an advantage. 
     SUMMARY 
     According to its major aspects, the present disclosure presents a lineal retainer kit for solving the afore-described problems. A lineal retainer kit is a system of components that cooperate together to achieve this desired result. The primary components of the kit are a lineal retainer, two splines, a cap and fasteners. The kit may also include mesh screening. In particular, the kit provides the infrastructure to enable homeowners or contractors to tailor the environment and appearance of a porch to meet the homeowner&#39;s individual requirements. 
     A feature of the disclosure is the Homeowners may apply a covering to just one side or to both sides. Mesh covering may be left up all year; a plastic film may be put up in colder months as a cost effective way to winterize the porch and provide a greenhouse effect, keeping the porch warmer for outdoor plants and seedlings than if they were exposed to cold winds and frost. Putting up a covering and taking it down can be done quickly and simply by removing the splines temporarily until the change is made. 
     Another feature of the disclosure is that the present lineal retainer kit can be used with greenhouses, with a covering of mesh or bird netting on one side and plastic on the other. 
     A feature of the disclosure is a lineal retainer with grooves on two opposing sides and with a third groove on the side adjacent to both of the opposing sides. There are two splines, one for each of the two opposing grooves and a cap that covers the third groove. The splines for the opposing grooves hold mesh screens or sheeting, such as plastic film or fabric, in place. 
     The long dimension of the lineal retainer defines a major axis and the grooves formed in the lineal retainer run parallel to this axis. Each grooved side of the lineal retainer has a face. When the splines are in place in their respective grooves holding the mesh screen or sheeting in place and the cap is in place in the third groove, the splines and cap will all be flush with the faces of their respective sides of the lineal retainer, for a trim appearance. 
     A feature of the disclosure is that the two opposing grooves and splines can be used to secure two materials covering the opening defined by the framing at the same time, such as screen mesh and plastic sheeting, or screen mesh and a fabric. The sheeting may provide shade, protection from wind or UV rays, noise reduction, and privacy, and may also be used to enhance the appearance of the house or the décor of the porch. 
     Another aspect of the disclosure is the splines. The splines may be flat splines and used when the two opposing grooves are flat spline grooves, or they may be U-shaped splines that fit into rectangular grooves, wherein each U-shaped spline has two opposing walls that engage the two opposing sides of a groove. The corresponding rectangular groove and the U-shaped spline may be configured to resist removal of the spline from the groove, such as by use of ribs and grooves formed in them and running parallel to the major axis of the lineal retainer on the sides of the groove and the corresponding walls of the spline. 
     An aspect of the disclosure is the third groove which may be V-shaped or may have a V-shaped notch in its bottom surface to facilitate accurate centering of each fastener of a row of fasteners, such as screws, to pass through the center of the V and also through the major axis of the lineal retainer and thence into the framing. 
     Those skilled in porch construction will appreciate other features from a careful reading the detailed description below, accompanied by the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the figures, 
         FIG. 1  is a perspective, partially cutaway view of the present lineal retainer kit installed and in use, according to an aspect of the disclosure; 
         FIG. 2  is an exploded end view of the lineal retaining kit, according to an aspect of the disclosure; 
         FIG. 3  is an assembled end view of the lineal retaining kit, according to an aspect of the disclosure; 
         FIG. 4 . is an alternative embodiment of the lineal retaining kit, according to an aspect of the disclosure; and 
         FIG. 5  illustrates a second alternative embodiment of the lineal retainer and cap, according to an aspect of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The term lineal is used in connection with windows to refer to trim pieces that are relatively long, thin pieces made of wood or extruded vinyl. As used therein, the term lineal retainer is intended to refer to a relatively long, relatively thin piece intended to be used with the openings of porch framing to retain, or hold, screening and sheeting. Lineals in windows unify and accent the exterior around a window as a secondary consideration. The term is used as a secondary consideration in the same way here, namely, for a component used to unify and accent the window. The lineal retainer, together with the other kit components, is primarily intended for holding mesh screens and sheeting in place as window coverings. 
     The term kit refers to a group of individual elements that may be provided together or used together to achieve a specific result, herein, covering the opening defined by the framing of the porch. Because porches are not standardized, of course, lineal retainers, splines, caps, mesh screening and sheeting will need to be cut to fit. Generally, the length of lineal retainer, cap, splines, and the number of fasteners in a kit or sold together for use will bear a relationship with each other that is closely related to the total length of the perimeters of the openings in the framing of a porch. 
     Referring now to the figures,  FIG. 1  shows the present lineal retainer kit installed in an opening defined by framing  10 . A porch is constructed by framing in the perimeter of the porch using horizontal and vertical posts and rails, collectively, herein referred to as framing  10 . Framing  10  may be formed from standard sizes of lumber secured together to have vertical posts and horizontal rails. Framing  10  defines openings  14  in the framing between posts and rails. 
     Openings  14  are then covered by mesh screening. Mesh screening are made of loosely woven strands of a wire-like material which may be fiberglass or aluminum. Other materials can also be used, including netting. In  FIG. 1 , a mesh screen  18  is shown covering opening  14 . A sheet  22  of plastic or textile is shown covering the opening in a plane parallel to mesh screen  18 . Both are held fast by the same pair of lineal retainers  26 ,  30 , with lineal retainer  26  oriented horizontally and lineal retainer  30  being vertically oriented. Hereinafter, because lineal retainer  26  is identical to lineal retainer  30  except for orientation, reference to lineal retainer  26  will be understood as applying to lineal retainer  30 . Lineal retainer  26  may be straight cut or miter cut from a longer lineal retainer  26  to the desired length using a saw or miter box or other stable cutting platform and cutting tool. 
     As best seen in  FIG. 2 , lineal retainer  26  has a first and an opposing second side  34 ,  38 . Each side  34 ,  38  has a face  42 ,  46 , exposed on one side or the other of opening  14 . First and second grooves  50 ,  54 , are formed in first and second sides  34 ,  38 , respectively. A first and a second spline  58 ,  62 , are seated in first and second grooves  50 ,  54 . The long dimension of lineal retainer  26  defines a major axis A, and first and second grooves  50 ,  54  run parallel to major axis A. Splines  58 ,  62  also run parallel to major axis A and are more or less coaxial with grooves  50 ,  54 . 
     First and second grooves  50 ,  54 , may have the same shape or may have different shapes. Primarily, they must be capable of holding a spline such as splines  58 ,  62 , in place and, together with the spline, hold the marginal portion of mesh screen  18  or sheet  22 . In  FIGS. 1-3 , first and second splines  58 ,  62 , are illustrated as having the same, generally rectangular U-shape but they may, in the alternative, be different. 
     Splines  58 ,  62 , are made of a resilient material such as natural or synthetic rubber, to assist in installing them in grooves  50 ,  54 . As seen in  FIG. 2 , especially, grooves  50 ,  54 , are essentially rectangular grooves with flat bottoms  52 ,  56 , and opposing flat sides  60 ,  64 , perpendicular to bottoms  52 ,  56 , respectively. Splines  58 ,  62  are shown as having an exterior shape of a rectangular solid but are U-shaped with two walls  44 ,  48 , and two legs  76 ,  80 , when viewed along major axis A (identified in  FIG. 1 ). 
     Splines  58 ,  62 , when seated in grooves  50 ,  54 , present a flat, smooth appearance from the exterior of lineal retainer  26 , may be configured to resist removal from grooves  50 ,  54 . For example, by forming a combination of ribs and grooves on walls  44 ,  48 , and sides  60   64 , parallel to the major axis A of lineal retainer  26 , the interlocking of ribs and grooves will resist lateral movement of splines  58 ,  62 . As best seen in  FIGS. 2 and 3 , ribs  66 ,  68 , on splines  58 ,  62  and grooves  70 ,  72 , on grooves  50 ,  54 , are easily formed when lineal retainer  14  and splines  58 ,  62  are extruded. Other variations of ribs and grooves and mixes of ribs and grooves are also possible. 
     Splines  58 ,  62 , because of their U-shape and the resilient material of which they are made can be easily inserted into grooves  50 ,  54 , by squeezing legs  76 ,  80 , together, and inserting them first into grooves  50 ,  54 . When legs  74 ,  78 , are released, they spring apart. The ribs  66 ,  68 , on walls  44 ,  48 , of splines  58 ,  62 , slip into the grooves  70 ,  72 , respectively, of grooves  50 ,  54 , to thereafter resist removal of splines  58 ,  62 . Splines  58 ,  62 , may be nonetheless be removed from grooves  50 ,  54 , respectively, because of their resilience if sufficient force is used. Ribs  66 ,  68 , and grooves  70 ,  72 , merely require intentional effort for their removal and are not removed, for example, as the result of, say, wind blowing on sheet  22 . 
     Third groove  82  and cap  86  hide fasteners  90  from the exterior when cap  86  is fitted in third groove  82 . Fasteners  90  can be screws or nails dimensioned to pass from third groove  82  through lineal retainer  14  and into framing  10  far enough to hold lineal retainer  14 , splines  58 ,  62  and mesh screen  18  and sheet  22  even against brisk winds. Third groove  82  may be V-shaped or have a V-notch  94  cut in its floor  98  to identify and facilitate locating and driving of fastener  90  into lineal retainer  14  and framing  10 . Fastener  90  should pass from V-notch  94  of third groove  82  through major axis A. Alternatively, holes can be pre-drilled into lineal retainer  14 , When fastener  90  is seated in third groove  82 , cap  86  can be set in place so no fastener  90  is exposed. 
     The lineal retainer which may be about 4 cm (1.5 inches) square, may be extruded of plastic such as PVC or aluminum in various colors, and the framing to which it attached may have a finish that matches or complements the color of the lineal retainer. Likewise the cap may be extruded PVC or aluminum in the same color and the spline may be made of synthetic rubber in any suitable color. If made of extruded plastic PVC, the plastic may be solid, foamed, or hollow PVC. 
       FIG. 4  illustrates an alternative embodiment of the disclosure, namely, a retainer  114  having flat spline grooves  98 ,  102 , that receive flat splines  106 ,  110 . A cap  118  covers a third groove  122 . 
       FIG. 5  illustrates a second alternative embodiment of the disclosure in a lineal retainer  130  with three grooves: two spline grooves  134 ,  138 , and one cap groove  142 . Grooves  134 ,  138 ,  142  are identical, and a cap  146  made of solid PVC or similar plastic may also serve as a spline. Each groove  134 ,  138 ,  142 , flares near its respective bottom  150 ,  154 ,  158 , and spline  148  has a complementary shape that extends into the flare of bottom  150 ,  154 ,  158 , respectively. Spline  148  may be made of solid or foamed PVC. The two spline-receiving grooves need not be identical but may be different and their splines configured accordingly. 
     When introducing elements of the present disclosure or exemplary aspects or embodiment(s) thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Although this disclosure has been described with respect to specific embodiments, the details of these embodiments are not to be construed as limitations.

Summary:
A lineal retainer kit for facilitating the covering of openings defined by porch framing with mesh screening and a second material. The primary components of the kit are a lineal retainer, two splines for the two opposing grooves in the lineal retainers, a cap, and fasteners to hold the lineal retainers to the framing, and possibly also including mesh screening material. The lineal retainers use opposing grooves and splines to hold two different coverings, such as mesh screening and plastic film or a fabric, at the same time. In particular, the kit enables homeowners or contractors to tailor the environment of a porch to better meet the homeowner&#39;s needs by providing an easy way to add shade, privacy, ultraviolet light protection, or a different aspect of the porch decor.